High Stability Polyionic Liquid Salts

ABSTRACT

Polyionic liquid salts are provided comprising polycationic or polyanionic molecules. Further provided are solvents comprising one or more polyionic liquid salts, and the use of such polyionic liquid salts as stationary phases in gas chromatography, and as a reagent in electrospray ionization-mass spectrometry (ESI-MS).

This application claims priority to U.S. provisional application Ser.No. 60/898,843 filed on 31 Jan. 2007, the disclosure of which isincorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

One of the more rapidly growing areas of chemistry research involvesionic liquids (ILs) and room temperature ionic liquids (RTILs). The widerange of possible cation and anion combinations allows for a largevariety of tunable interactions and applications. The uses andapplications of RTILs have traversed many areas of chemistry and evenareas of biochemistry. Reported thermal stability ranges of 300° C. insome cases, their ability to solubilize a variety of disparatemolecules, and the fact that ionic liquids can be synthesized that areimmiscible with both water and nonpolar organic solvents further add totheir usefulness. While much work involving RTILs deals with their useas “green” solvents in organic synthesis, their characterization and theunderstanding of their unique physico-chemical and solvation propertiesare important areas of ongoing investigation. Some research in the fieldof ionic liquids has explored their fundamental properties in hopes thatit would become apparent which cation-anion combinations give rise tospecific and/or desired qualities. Thus far, this approach has met withonly limited success.

Early work seemed to indicate that the anionic constituents of ionicliquids may have a greater influence on their physical and chemicalproperties. However, this notion may be due, in part, to the fact thatthe ionic liquids studied contained not only a variety of differentanions, but closely related, structurally similar cations. Indeed,anions such as halides possess higher hydrogen bond basicity character(Cl>Br>I) and readily hydrogen bond to generally form viscous liquids.This is not to say that only coordinating anions produce viscousliquids; it is well known that the viscosity of1-alkyl-3-methylimidazolium ionic liquids is found to increase withincreasing alkyl chain length even when paired with non-coordinatinganions such as hexafluorophosphate (PF₆ ⁻) andbis(trifluoromethylsulfonyl)imide (NTf₂ ⁻). While the cation and itsstructure can certainly influence the surface tension, melting point,viscosity, density, and thermal stability as well as interact viadipolar, π-π, and eta-π interactions with dissolved molecules, its rangeof effects has not been studied as extensively as it has for anions.

Despite their touted stability, many of the more common ionic liquidsare susceptible to chemical and thermal degradation. Recently, it wasreported that when 1-butyl-3-methylimidazolium chloride (BMIM-Cl) isexposed to the atmosphere and heated, it begins to turn from a paleyellow to amber color at 120° C. When heated further, the ionic liquidbegins to show obvious signs of decomposition at and above 150° C. Mostrecently, a new class of “high stability ionic liquids” based on bulkycations and triflate anions was introduced and it was reported that therobustness of some of the more traditional ionic liquids appears to beless than previously thought (in terms of both lower thermal stabilityand higher volatility). MacFarlane and co-workers reached similarconclusions via use of the ‘step tangent method’ for thermogravimetricanalysis (TGA) to more accurately determine degradation temperatures ofimidazolium-based cations. They point out that significant evolution ofvolatile degradation products takes place well below previously reporteddegradation temperatures. A maximum operating temperature parameter wasproposed to provide a more appropriate estimate of thermal stabilityusing TGA.

Techniques of solid phase extraction and solid phase microextraction areknown. Ionic liquids have been used in task-specific liquid-liquidextraction for use in extraction of Hg²⁺ and Cd²⁺ from water. U.S.Patent Publication No. 2006/0025598 reports the use of diionic liquidsalts and immobilized ionic liquids for solid phase extraction. U.S.Pat. No. 6,531,241 reports cyclic delocalized cations joined together byspacer groups.

SUMMARY OF THE INVENTION

In one embodiment, a polyionic liquid salt is provided. The polyionicliquid salt comprises a polyionic species that corresponds in structureto Formula I:

Gc(A)_(m)  (I)

and at least one counterion;

Gc is a non-charged substitutable central group selected from the groupconsisting of nitrogen atom, phosphorous atom, silicon atom, alkyl,carbocyclyl, and heterocyclyl; wherein the nitrogen atom optionally issubstituted with one or more substituents selected from the groupconsisting of alkyl and alkylcarbonylaminoalkyl;

-   -   wherein Gc optionally is further substituted with one or more Rc        substituents independently selected from the group consisting of        alkyl, cycloalkyl, phenyl, halo, alkoxy and hydroxyl;

each A is an independently selected monoionic group, wherein:

the monoionic group is selected from the group consisting of alkylene,alkenylene, alkynylene, (—CH₂-carbocyclyl-CH₂—)_(n), and polysiloxyl;wherein alkylene, alkenylene, and alkynylene optionally contain one ormore heteroatoms selected from the group consisting of O, N, S and Si;

-   -   wherein the monoionic group is substituted with a cationic group        selected from the group consisting of heterocyclyl, ammonium and        phosphonium; wherein the cationic group optionally is        substituted with one or more substituents independently selected        from the group consisting of alkyl, cycloalkyl, phenyl, halo,        alkoxy and hydroxyl; wherein the alkyl optionally is substituted        with one or more substituents selected from the group consisting        of hydroxy and phenyl; or    -   the monoionic group is an anionic group selected from the group        of substituents consisting of carboxylate, sulfonate and        sulfate; wherein each such substituent is optionally substituted        with one or more substituents independently selected from the        group consisting of alkyl, carbocyclyl and heterocyclyl;

n is selected from the group consisting of 1 to 20, inclusive; and

m is selected from the group consisting of 3, 4, 5 and 6.

In another embodiment, a further polyionic liquid salt is provided. Thepolyionic liquid salt comprises a polyionic species having Formula(III), (IV) or (V):

and at least one counterion;wherein each B is independently selected from the group consisting ofalkylene, alkenylene, alkynylene, (—CH₂-carbocyclyl-CH₂—)_(n), andpolysiloxyl;

-   -   wherein alkylene, alkenylene, and alkynylene optionally contain        one or more heteroatoms selected from the group consisting of O,        N, S or Si;    -   wherein B is optionally substituted with one or more        substituents selected from the group consisting of alkyl,        alkenyl, alkynyl, and alkoxy;

each A is an independently selected monoionic group, wherein:

-   -   the monoionic group is a cationic group selected from the group        consisting of heterocyclyl, ammonium and phosphonium; wherein        the cationic group optionally is substituted with one or more        substituents independently selected from the group consisting of        alkyl, cycloalkyl, phenyl, halo, alkoxy and hydroxyl; wherein        the alkyl optionally is substituted with one or more        substituents selected from the group consisting of hydroxy and        phenyl; or    -   the monoionic group is an anionic group selected from the group        of substituents consisting of carboxylate, sulfonate and        sulfate; wherein each such substituent is optionally substituted        with one or more substituents independently selected from the        group consisting of alkyl, carbocyclyl and heterocyclyl;

n is selected from the group consisting of 1 to 20, inclusive.

In a further embodiment, a solvent is provided comprising one or morepolyionic liquid salts as defined herein.

In a further embodiment, a device is provided for chemical separation oranalysis comprising a solid support and one or more polyionic liquidsalts as defined herein, wherein the one or more polyionic liquid saltsis adsorbed, absorbed or immobilized on the solid support.

In a further embodiment, a method for separating one chemical from amixture of chemicals is provided. The method comprises:

providing a mixture of at least one first and at least one secondchemical;

exposing the mixture to a solid support containing one or more polyionicliquid salts as defined herein; wherein the one or more polyionic liquidsalts is adsorbed, absorbed or immobilized on the support, and retainingat least a portion of the first chemical on the solid support.

In a further embodiment, a method of detecting an anion by ESI-MS isprovided. The method comprises using one or more polycationic liquidsalts as defined herein.

Other embodiments, including particular aspects of the embodimentssummarized above, will be evident from the detailed description thatfollows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an embodiment of a syringe useful for SPME and SPME/MALDI massspectrometry.

FIG. 2 is another embodiment of a syringe useful for SPME and SPME/MALDImass spectrometry.

FIG. 3 is graphical representation comparing the signal to noise ratiosin the positive (I, II) and negative (III, IV) ion modes for the twoanions, hexachloroplatinate and o-benzenedisulfonate. Tricationicreagents A6 (I) and B1 (II) in water were introduced into the carrierflow after anion injection in positive ion mode while only water wasused in negative ion mode (III, IV).

DETAILED DESCRIPTION

While the specification concludes with the claims particularly pointingout and distinctly claiming the invention, it is believed that thepresent invention will be better understood from the followingdescription.

A. DEFINITIONS

The term “carbocyclyl” (alone or in combination with another term(s))means a saturated cyclic (i.e., “cycloalkyl”), partially saturatedcyclic (i.e., “cycloalkenyl”), or completely unsaturated (i.e., “aryl”)hydrocarbyl substituent containing from 3 to 14 carbon ring atoms (“ringatoms” are the atoms bound together to form the ring or rings of acyclic substituent). A carbocyclyl may be a single-ring (monocyclic) orpolycyclic ring structure.

A carbocyclyl may be a single ring structure, which typically containsfrom 3 to 7 ring atoms, more typically from 3 to 6 ring atoms, and evenmore typically 5 to 6 ring atoms. Examples of such single-ringcarbocyclyls include cyclopropyl (cyclopropanyl), cyclobutyl(cyclobutanyl), cyclopentyl (cyclopentanyl), cyclopentenyl,cyclopentadienyl, cyclohexyl (cyclohexanyl), cyclohexenyl,cyclohexadienyl, and phenyl.

A carbocyclyl may alternatively be polycyclic or contain more than onering. Examples of polycyclic carbocyclyls include bridged, fused,spirocyclic, and isolated carbocyclyls. In a spirocyclic carbocyclyl,one atom is common to two different rings. An example of a spirocycliccarbocyclyl is spiropentanyl. In a bridged carbocyclyl, the rings shareat least two common non-adjacent atoms. Examples of bridged carbocyclylsinclude bicyclo[2.2.1]heptanyl, bicycle[2.2.1]hept-2-enyl, andadamantanyl. In a fused-ring carbocyclyl system, multiple rings may befused together, such that two rings share one common bond. Examples oftwo- or three-fused ring carbocyclyls include naphthalenyl,tetrahydronaphthalenyl (tetralinyl), indenyl, indanyl (dihydroindenyl),anthracenyl, phenanthrenyl, and decalinyl. In an isolated carbocyclyl,the rings are separate and independent, as they do not share any commonatoms, but a linker exists between the rings.

The term “carbocyclyl” encompasses protonated carbocyclyls, such as

The term “heterocyclyl” (alone or in combination with another term(s))means a saturated (i.e., “heterocycloalkyl”), partially saturated (i.e.,“heterocycloalkenyl”), or completely unsaturated (i.e., “heteroaryl”)ring structure containing a total of 3 to 14 ring atoms. At least one ofthe ring atoms is a heteroatom (i.e., N, P, As, O, S and Si), with theremaining ring atoms being independently selected from the groupconsisting of carbon, oxygen, nitrogen, and sulfur. A heterocyclyl maybe a single-ring (monocyclic) or polycyclic ring structure.

The term heterocyclyl encompasses protonated heterocyclyls such aspyridinium, pyridazinium, pyrimidinium, pyrazinium, imidazolium,pyrazolium, thazolium, oxazolium and triazolium.

A heterocyclyl may be a single ring, which typically contains from 3 to7 ring atoms, more typically from 3 to 6 ring atoms, and even moretypically 5 to 6 ring atoms. Examples of single-ring heterocyclylsinclude furanyl, dihydrofuranyl, tetrahydrofuranyl, thiophenyl(thiofuranyl), dihydrothiophenyl, tetrahydrothiophenyl, pyrrolyl,pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolinyl, imidazolidinyl,pyrazolyl, pyrazolinyl, pyrazolidinyl, triazolyl, tetrazolyl, oxazolyl,oxazolidinyl, isoxazolidinyl, isoxazolyl, thiazolyl, isothiazolyl,thiazolinyl, isothiazolinyl, thiazolidinyl, isothiazolidinyl,thiodiazolyl, oxadiazolyl (including 1,2,3-oxadiazolyl,1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl (furazanyl), or 1,3,4-oxadiazolyl),oxatriazolyl (including 1,2,3,4-oxatriazolyl or 1,2,3,5-oxatriazolyl),dioxazolyl (including 1,2,3-dioxazolyl, 1,2,4-dioxazolyl,1,3,2-dioxazolyl, or 1,3,4-dioxazolyl), oxathiazolyl, oxathiolyl,oxathiolanyl, pyranyl, dihydropyranyl, thiopyranyl,tetrahydrothiopyranyl, pyridinyl (azinyl), piperidinyl, diazinyl(including pyridazinyl (1,2-diazinyl), pyrimidinyl (1,3-diazinyl), orpyrazinyl (1,4-diazinyl)), piperazinyl, triazinyl (including1,3,5-triazinyl, 1,2,4-triazinyl, and 1,2,3-triazinyl)), oxazinyl(including 1,2-oxazinyl, 1,3-oxazinyl, or 1,4-oxazinyl)), oxathiazinyl(including 1,2,3-oxathiazinyl, 1,2,4-oxathiazinyl, 1,2,5-oxathiazinyl,or 1,2,6-oxathiazinyl)), oxadiazinyl (including 1,2,3-oxadiazinyl,1,2,4-oxadiazinyl, 1,4,2-oxadiazinyl, or 1,3,5-oxadiazinyl)),morpholinyl, azepinyl, oxepinyl, thiepinyl, and diazepinyl.

A heterocyclyl may alternatively be polycyclic or contain more than onering. Examples of polycyclic heterocyclyls include bridged, fused, andspirocyclic heterocyclyls. In a spirocyclic heterocyclyl, one atom iscommon to two different rings. In a bridged heterocyclyl, the ringsshare at least two common non-adjacent atoms. In a fused-ringheterocyclyl, multiple rings may be fused together, such that two ringsshare one common bond. Examples of fused ring heterocyclyls containingtwo or three rings include indolizinyl, pyranopyrrolyl, 4H-quinolizinyl,purinyl, naphthyridinyl, pyridopyridinyl (includingpyrido[3,4-b]-pyridinyl, pyrido[3,2-b]-pyridinyl, orpyrido[4,3-b]-pyridinyl), and pteridinyl. Other examples of fused-ringheterocyclyls include benzo-fused heterocyclyls, such as indolyl,isoindolyl (isobenzazolyl, pseudoisoindolyl), indoleninyl(pseudoindolyl), isoindazolyl (benzpyrazolyl), benzazinyl (includingquinolinyl (1-benzazinyl) or isoquinolinyl (2-benzazinyl)),phthalazinyl, quinoxalinyl, quinazolinyl, benzodiazinyl (includingcinnolinyl (1,2-benzodiazinyl) or quinazolinyl (1,3-benzodiazinyl)),benzopyranyl (including chromanyl or isochromanyl), benzoxazinyl(including 1,3,2-benzoxazinyl, 1,4,2-benzoxazinyl, 2,3,1-benzoxazinyl,or 3,1,4-benzoxazinyl), and benzisoxazinyl (including 1,2-benzisoxazinylor 1,4-benzisoxazinyl).

As used herein, the term “alkyl” (alone or in combination with anotherterm(s)) refers to an alkane-derived radical containing from 1 to 20,carbon atoms. Alkyl includes straight chain alkyl, branched alkyl andcycloalkyl. Straight chain or branched alkyl groups contain from 1-15carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl,and the like. Alkyl also includes straight chain or branched alkylgroups that contain or are interrupted by one or more cycloalkylportions. Examples of this include, but are not limited to,4-(isopropyl)-cyclohexylethyl or 2-methyl-cyclopropylpentyl. The alkylgroup is attached at any available point to produce a stable compound.The term alkyl is also meant to encompass a fully substituted carbon.

The term “alkylene” (alone or in combination with another term(s))refers to a divalent alkane-derived radical containing 1-20, preferably1-15, carbon atoms, from which two hydrogen atoms are taken from thesame carbon atom or from different carbon atoms. Examples of alkyleneinclude, but are not limited to, methylene—CH.₂—, ethylene —CH.₂CH.₂—,and the like.

The term “polysiloxyl” (alone or in combination with another term(s))refers to a divalent radical composed of oxygen and silicon containing1-20 atoms. Examples include (—Si—O—Si—)_(n); wherein n is from 1-20.

The term “amino” (alone or in combination with another term(s)) means—NH₂. The term amino is meant to encompass a “monosubstituted amino”(alone or in combination with another term(s)) wherein one of thehydrogen radicals is replaced by a non-hydrogen substituent; and a“disubstituted amino” (alone or in combination with another term(s))wherein both of the hydrogen atoms are replaced by non-hydrogensubstituents, which may be identical or different.

The term “alkoxy” (alone or in combination with another term(s)) meansan alkylether, i.e., —O-alkyl. Examples of such a substituent includemethoxy (—O—CH₃), ethoxy, n-propoxy, isopropoxy, n-butoxy, iso-butoxy,sec-butoxy, tert-butoxy, and the like.

The term “aralkyl” (alone or in combination with another term(s)) refersto the group —R— Ar where Ar is an aryl group and R is lower alkylene orsubstituted lower alkylene group. The aryl functionality of aralkyl canoptionally be unsubstituted or substituted with, e.g., halogen, loweralkyl, alkoxy, alkylthio, acetylene, amino, amido, carboxyl, hydroxyl,aryl, aryloxy, heterocycle, substituted heterocycle, hetaryl,substituted hetaryl, nitro, cyano, thiol, sulfamido, and the like.

The term “ammonium” refers to a positively charged polyatornic cation ofthe chemical formula NH₄ ⁺. Ammonium also embraces positively charged orprotonated substituted amines (such as protonated tertiary amine) andquaternary ammonium cations, N⁺R₄, where one or more hydrogen atoms arereplaced by organic radical groups (which is symbolized as R above).

Similarly, the term “phosphonium” refers to a positively chargedpolyatomic ion with the chemical formula PH₄ ⁺. Phosphonium may also besubstituted where one or more hydrogen atoms are replaced by organicradical groups.

All percentages and ratios used herein are by weight of the totalcomposition and all measurements made are at 25° C. and normal pressureunless otherwise designated. All temperatures are in Degrees Celsiusunless specified otherwise. The present invention can comprise (openended) or consist essentially of the components of the present inventionas well as other ingredients or elements described herein. As usedherein, “comprising” means the elements recited, or their equivalent instructure or function, plus any other element or elements which are notrecited. The terms “having” and “including” are also to be construed asopen ended unless the context suggests otherwise. As used herein“consisting essentially of” means that the invention may includeingredients in addition to those recited in the claim, but only if theadditional ingredients do not materially alter the basic and novelcharacteristics of the claimed invention. Preferably, such additiveswill not be present at all or only in trace amounts. However, it may bepossible to include up to about 10% by weight of materials that couldmaterially alter the basic and novel characteristics of the invention aslong as the utility of the compounds (as opposed to the degree ofutility) is maintained. All ranges recited herein include the endpoints,including those that recite a range “between” two values. Terms such as“about”, “generally”, “substantially”, and the like are to be construedas modifying a term or value such that is not an absolute, but does notread on the prior art. Such terms will be defined by the circumstancesand the terms that they modify as those terms are understood by those ofskill in the art. This includes, at the very least, the degree ofexpected experimental error, technique error, and instrument error for agiven technique used to measure a value.

In its broadest sense, a “polyionic salt” or “PSI” is a salt formedbetween a polyionic species or “polyon” as described herein and one ofmore counterions of equal total charge. If a polyon has three cationicgroups then one or more counterions would be necessary to provide acharge balance, e.g., −3. This could be achieved by using threemonoanionic species, one monoanionic species and one dianionic species,or one trianionic species. The resulting salt in accordance with theinvention is preferably a liquid at a temperature at about 100° C. orlower, more preferably at 25° C. or lower. A polyon, as used herein,refers to an ion, either a cation or an anion, which has n charges,where n is at least 3, i.e., n is 3, 4, 5 or an integer greater than 5.As used herein, this term is not meant to embrace a single chargedspecies that has the specific total charge, e.g., a +3 ion such as Al⁺³or a −3 ion such as PO₃ ⁻³. Rather it contemplates a single moleculewith at least three discrete monoionic groups, each individuallycovalently bound to a central group. As used herein, the term“covalently bound” is meant that the two molecular moieties, e.g., amonoionic group and the central group, are linked via a covalent bond.Preferably, the monoionic groups do not form a covalent bond directlywith each other. Preferably, the central group is not charged.

The monoionic groups in a polyon should be of the same charge. They maybe different types of groups or the polyionic liquid salts may be“geminal” which means all ionic groups are not only the same charge, butalso the same structure. The counterions need not be identical either.In one embodiment, either the polyon or the salt forming species ischiral, having at least one stereogenic center. The monoionic groups mayalso contain substituents which are themselves chiral. The central groupmay also be chiral or contain one or more chiral substituents. In suchinstances, the polyionic liquid salts, may be racemic (or in the case ofdiastereomers, each pair of enantiomers is present in equal amounts) orthey may be optically enhanced. “Optically enhanced” in the case ofenantiomers means that one enantiomer is present in an amount which isgreater than the other. In the case of diastereomers, at least one pairof enantiomers is present in a ratio of other that 1:1. Indeed, thepolyionic liquid salts may be “substantially optically pure” which oneenantiomer or, if more than one stereogenic center is present, at leastone of the pairs or enantiomers, is present in an amount of at leastabout 90% relative to the other enantiomer. The polyionic liquid of thesalts of the invention may also be optically pure, i.e., at least about98% of one enantiomer relative to the other.

Usually, the term polyionic salt is used to describe a salt molecule,although, as the context suggests, is may be used synonymously with“polyionic liquid” (PIL”) and “polyionic liquid salt” (“PILS”). A“polyionic liquid” or “PIL” in accordance with the present invention isa liquid comprised of polyionic salts. Thus, sufficient PIS moleculesare present such that they exist in liquid form at the temperaturesindicated herein. This presumes that a single PIS molecule is not aliquid. A PIL is either a polycationic ionic liquid or a polyanionicionic liquid (a liquid comprising either polycationic salts orpolyanionic salts as described herein) or a mixture thereof. PILS mayalso be mixed with other solvents that are not PILS. Any polycationicionic liquid which is stable and has a solid/liquid transformationtemperature of about 500° C. or lower, more preferably about 400° C. orlower is contemplated. The same is true for “polyanionic ionic liquids”also known as “liquid salts of a polyanion”, except the charges arereversed. Polycationic liquids and polyanionic liquids can also bereferred to herein as polyionic liquid salts (“PILS” or “PCLS” and“PALS” depending upon charge). A polyon which contains three mono-ionicgroups is also termed a triion.

B. POLYIONIC LIQUID SALTS

This invention is directed, in part, to polyionic liquid saltscomprising a polyionic species and at least one counterion.

In some embodiments, the polyionic liquid species comprise at least onepolyanionic or polycationic liquid salt molecule.

In some embodiments, the polyionic liquid salt comprising a polyionicspecies having at least three discrete monoionic groups and anappropriate number of counterions. The polyionic liquid salt does notsubstantially decompose nor substantially volatilize at a temperature ofabout 200° C. or lower and have a solid/liquid transformationtemperature of about 100° C. or lower and/or a liquid range of at leastabout 200° C. In a particular embodiment, the polyionic liquid salt hasa solid/liquid transformation temperature of about 25° C. or lower.

B1. Central Group Polyionic & Non-Central Group Polyionic Salts

In one embodiment, the monoionic groups in the polyionic species areindividually covalently bound to a non-charged central group. Suchpolyionic liquid salts are termed central group polyionic liquid salts(CGPs). The polyionic species can be polyanionic or polycationic.

In some embodiments, central group polyionic salts are of the structureof Formula Gc(A)_(m), wherein Gc is the central group, each A is amonoionic group and m, which is at least three, is the number of suchgroups in the polyionic species.

In some embodiments, the polyionic species corresponds in structure toFormula I:

Gc(A)_(m)  (I)

wherein Gc, m and each A can be as defined hereinafter.

In some embodiments, the polyionic species corresponds in structure toFormula II:

Gc(A)₃  (II)

wherein Gc and each A can be as defined hereinafter.

In some embodiments, the polyionic species corresponds in structure toFormula VI:

Gc(A)₄  (IV)

wherein Gc and each A can be as defined hereinafter.

In another embodiment, the polyionic species does not include a centralgroup. These are termed as Non-Central Group Polyons or “NCGPs.” Thesepolyons can have generally linear, branched or even cyclic structures.The monoionic A groups are separated by bridging groups, B. Each NCGPwill include at least three monoionic groups as previously defined inconnection with CGPs and each group may be as previously defined for(A)_(m).

Each A and B may, where present, be the same or different.

In some embodiments, the polyionic species corresponds in structure toFormula III:

A-B-A-B-A  (III)

wherein each A and B can be the same or different and as definedhereinafter.

In some embodiments, the polyionic species corresponds in structure toFormula IV:

wherein each A and B can be the same or different and as definedhereinafter.

In some embodiments, the polyionic species corresponds in structure toFormula V:

A-B-A-B-A-B-A  (V)

wherein each A and B can be the same or different and as definedhereinafter.

B2. Polyionic Liquid Salt Stability & Volatility

In some embodiments, the polyionic liquid salts are stable and willneither substantially decompose nor substantially volatilize, asmeasured as described herein, at a temperature of about 200° C. or lowerand will have a temperature of solid/liquid transformation temperatureof about 100° C. or lower or a liquid range of at least about 200° C.

In another embodiment, the polyionic liquid salt has both a solid/liquidtransformation temperature of about 100° C. or lower and a liquid rangeof at least about 200° C. In a particular embodiment, the polyionicliquid salt containing the polyionic species of Formula (I) has asolid/liquid transformation temperature of about 100° C. or lower and/ora liquid range of 200° C. or higher and/or are substantiallynon-volatile and non-decomposable at temperatures below 200° C.

In a particular embodiment, a polycationic ionic liquid or polyanionicliquid will not substantially decompose or volatilize (or remainsubstantially non-volatile) as measured by being immobilized as a thinfilm in a fused silica capillary or on a silica solid support asdescribed herein, at a temperature of about 200° C. or lower. Othertypes of solid supports, such as diatomaceous earth (commonly used inpacked GC) carbons (e.g. Carbopack and Carboxen), metal particles (e.g.zirconia, titania, etc.), polymeric particles (e.g.styrene-divinylbenzene or SDVB) can be used in place of silica. This isin addition to the particles as described herein. Indeed, any mediauseful in chromatography can be used. “Substantially” in this contextmeans less than about 10% by weight will decompose or volatilize atabout 200° C. inside a capillary over the course of about one hour.Moreover, the polycationic ionic liquid in accordance with thisembodiment will preferably have either a solid/liquid transformationtemperature at about 100° C. or lower or a liquid range (the range oftemperatures over which it is in a liquid form without burning ordecomposing) of at least about 200° C.

In another particular embodiment, a polycationic ionic liquid will haveboth a solid/liquid transformation temperature at about 100° C. or lowerand a liquid range of at least 200° C.

In another particular embodiment, a polycationic ionic liquid will notsubstantially volatilize or decompose, as discussed herein, at atemperature of less than about 300° C. “Substantially” in this contextmeans that less than about 10% by weight will decompose or volatilize atabout 300° C. inside a capillary over the course of about one hour.Moreover, the polyvcationic ionic liquids in accordance with thisembodiment will preferably either have a solid/liquid transformationtemperature at 25° C. or lower.

In another particular embodiment, the polycationic ionic liquids willalso have a liquid range of at least about 200° C. In a furtherparticular embodiment, the liquid range will be about 300° C. or above.

In a particular embodiment, a polyanionic ionic liquid will notsubstantially decompose or volatilize as measured by being immobilizedas a this film in a fused silica capillary as described herein, at atemperature of about 200° C. or lower. Moreover, the polyanionic ionicliquid in accordance with this embodiment will have either asolid/liquid transformation temperature at about 100° C. or lower or aliquid range of at least about 200° C.

In another embodiment, these polyanionic ionic liquids will have both asolid/liquid transformation temperature at about 100° C. or lower and aliquid range (polyionic molecule is stable over the entire temperaturerange) or at least about 200° C.

In another embodiment, the invention provides a polyionic liquid salthaving a melting point of between about −10 and about −20° C.

In another aspect of the invention, a polyanionic ionic liquid will notsubstantially volatilize or decompose, as discussed herein, at atemperature of less than about 300° C. Moreover, the polyanionic ionicliquids in accordance with this embodiment will preferably have either asolid/liquid transformation temperature at about 25° C. or lower. Inanother embodiment, the polyanionic liquids will also have a liquidrange of at least 200° C. In an even more preferred aspect of theinvention, the liquid range will be about 300° C. or above.

Therefore, in one embodiment, a polyionic liquid salt is provided whichis either a polycationic ionic liquid salt or a polyanionic ionic liquidsalt which will neither substantially decompose nor volatilize, asmeasured as described herein, at a temperature of about 200° C. or lowerand will have a temperature of solid/liquid transformation temperatureof about 100° C. or lower or a liquid range of at least about 200° C.

In other aspects of the invention, these polyionic liquid salts willhave both a solid/liquid transformation temperature at about 100° C. orlower and a liquid range of at least about 200° C.

In other embodiments in accordance with the present invention, thepolyionic liquid salts, either polycationic or polyanionic will bestable, that is not substantially volatilized or decomposed, asdiscussed herein, at a temperature of less than about 300° C. and willhave a solid/liquid transformation temperature at about 25° C. or lower.In a particular embodiment of this aspect of the present invention, thepolyionic liquid salt has a liquid range of at least about 200° C. andeven more preferably at least about 300° C. Any polyionic compound whichcan form a stable liquid salt that meets the broadest parameters iscontemplated.

B3. Polyionic Species Symmetry

Polyionic species of the present invention can be classified assymmetric or unsymmetric.

In some embodiments, the polyionic species are symmetric.

By “symmetric,” it is meant that the polyionic species possess asymmetric central group and identical ionic groups (A)_(m). For example,a symmetric triionic species may contain three identical mono-ionicgroups attached to a central phenyl group at carbon 1, 3 and 5. Such atriionic species possesses C₃ symmetry with respect to the 3 mono-ionicgroups. This would still be considered symmetric even if the counterionsare different. If Gc is cycloheptane, the three monoionic groups couldnot be completely symmetrically attached and thus it is not symmetrical.

The polyionic species can also be center-symmetric. By“center-symmetric,” it is meant that the polyionic species possess asymmetric central group regardless whether the ionic groups, (A)_(m),are identical. For example, a center-symmetric triionic species maycontain three different monoionic groups attached to a central phenylgroup.

In other embodiments, the polyionic species are unsymmetric.

By “unsymmetric,” it is meant that the monoionic groups, A_(m), arestructurally different, or that the central group is unsymmetric, orthat the monoionic groups conjugate to the central group in such amanner that the polyionic species is not symmetric. The inventionencompasses unsymmetric polyionic species due to any compositionaland/or structural arrangement.

In some embodiments, an unsymmetric polyionic species of the inventioncontains different monoionic groups

For example, (A)_(m) can be different cations such as substituted orunsubstituted, saturated or unsaturated, straight or branched aliphaticchain, cyclic group, aromatic group, ammonium such as quaternaryammonium and protonated tertiary amine, phosphonium or arsonium group;or different anions such as substituted or unsubstituted, saturated orunsaturated, straight or branched aliphatic chain, cyclic group,aromatic group, carboxylate, sulfonate, and sulfate. In some otherembodiments, the central group is unsymmetric. For example, the centralgroup can be a 4-membered ring. In still some other embodiments, themonoionic groups conjugate to the central group in such a manner thatthe polyionic species is not symmetric. For example, the triionicspecies can contain 3 identical monoionic groups conjugated to carbon 1,2 and 4 of a benzene ring.

Although each individual types of unsymmetric features described aboveis sufficient for the polyionic species to be unsymmetric, a combinationof two or more types of unsymmetric features are also contemplated.

The unsymmetric polyionic salts of the invention can be used in asubstantially pure form in any of the applications, e.g., theapplications disclosed in this application. As compared to correspondingsymmetric polyionic salts, polyionic salts which do not have identicalmonoionic groups or which include an unsymmetric central group generallyhave lower melting temperatures, and advantage for “liquid” salts. Inaddition, the higher the degree of internal structural dissimilarity ascompared to corresponding symmetric polyionic salts, generally the lowerthe melting temperatures will result as compared to those of thecorresponding symmetric polyionic salts. The trend can be thought of asa continuum from a symmetric molecule on the one end and a group withall different counterions, all different ions, different substituents,and an unsymmetric central group on the other. The former would beexpected to have the highest melting point and the latter the relativelylowest. Of course, there can be variations to this trend. For example, aspecific counterion might have a greater effect on decreasing meltingpoint than the use of other different ions.

The unsymmetric polyionic salts of the invention may also beadvantageous for uses as solvents. For example, a triionic specieshaving three different A groups offers three sets of possibleinteractions with other molecules in the solution as compared to onlyone set in the case of a symmetric triionic species. Indeed, the moreunsymmetric, the more the variety of interactions that can result. Thus,the invention provides a use of a polyionic liquid of a substantiallypure “unsymmetric” polyionic salt as described above as a solvent.

The unsymmetric polyionic liquid salts of the invention can be used in asubstantially pure form in any of the applications, e.g., theapplications disclosed in this application. The unsymmetric polyionicsalts of the invention can also be used in combination with any of thesymmetric polyionic salts as a mixture. Thus, in one embodiment, theinvention provides a polyionic liquid of a substantially pureunsymmetric polyionic salt as described above. In another embodiment,the invention provides a polyionic liquid comprising at least one of theunsymmetric polyionic salts as described above and at least one of thesymmetric polyionic salts of the invention. A person skilled in the artwould be able to determine the proportion of the symmetric andunsymmetric polyionic liquid salts when used as a mixture according tothe particular application.

B4. (A)_(m)Substituent

In (A)_(m), each A is a monoionic group and m is the number of suchgroups in the polyionic liquid salt of the invention. A₃ therefore meansthat there are three monoionic groups just as A₅ means that there arefive monoionic groups. Each A may be the same or different so long asthey are all anions or all cations as appropriate.

In some embodiments, m is selected from the group consisting of 3, 4, 5,and 6.

In some embodiments, A is chiral and therefore contains at least onestereogenic center.

In some embodiments, each A is a cationic or anionic group.

In some embodiments, each A is a cationic group.

In some such embodiments, each A is cationic and is, without limitation,carbocyclyl, heterocyclyl, quaternary ammonium, protonated tertiaryamine, phosphonium or arsonium groups.

In some embodiments, each A is a monoionic group selected from the groupconsisting of alkylene, alkenylene, alkynylene,(—CH₂-carbocyclyl-CH₂—)_(n), and polysiloxyl; wherein alkylene,alkenylene, and alkynylene optionally contain one or more heteroatomsselected from the group consisting of O, N, S and Si;

-   -   wherein the monoionic group is substituted with a cationic group        selected from the group consisting of heterocyclyl, quaternary        ammonium, protonated tertiary amine and phosphonium; wherein the        cationic group optionally is substituted with one or more        substituents independently selected from the group consisting of        alkyl, cycloalkyl, phenyl, halo, alkoxy and hydroxyl; wherein        the alkyl optionally is substituted with one or more        substituents selected from the group consisting of hydroxy and        phenyl; and n is selected from the group consisting of 1 to 20,        inclusive.

In some such embodiments, each A is independently selected from thegroup consisting of:

wherein R₁, R₂, R₃ and R_(n) can be the same or different, and each ofR₁, R₂, R₃ and R_(n) can be hydrogen, substituted or unsubstituted,saturated or unsaturated, straight or branched aliphatic chain (such asalkyl), carbocyclyl (such as cycloalkyl or phenyl), heterocyclyl, halo,alkoxy, hydroxyl, hydroxyalkyl or aralkyl.

In other embodiments, each A is an anionic group.

In other such embodiments, each A is anionic and is, without limitation,substituted or unsubstituted, saturated or unsaturated, straight orbranched aliphatic, cyclic or aromatic group, carboxylate, sulfonate,and sulfate; wherein each such substituent is optionally substitutedwith one or more substituents independently selected from the groupconsisting of alkyl, carbocyclyl and heterocyclyl;

Typically, the structural considerations for polyionic liquids are thesame whether they are polyanionic ionic liquids or polycationic ionicliquids. First, the polyionic liquids will include a polyionic species,either a polyanionic or a polycationic molecule. The polyionic speciescontains three or more monoionic groups shown as (A)_(m) in Formula (I),and (A)₃ in Formula (II) separated by a center or central moiety asdiscussed herein. Any anion or cation that can be bound to a centralgroup to provide a polyanionic ionic liquid salt or polycationic ionicliquid salt is contemplated. These include those that are identifiedabove. Possible cations include, without limitation, quaternary ammonium(—NI₃)⁺, protonated tertiary amine (—NI₂H)⁺, a phosphonium and/or anarsonium group. These groups can be aliphatic, cyclic or aromatic.Anions may include, for example, carboxylates, sulfonates or sulfates.Examples of a dicarboxylic acid polyanion include, without limitation,succinic acid, nonanedioic acid and dodecanedioic acid.

In addition, hybrid polyanions and polycations are contemplated. Thus,for illustration only, a polycation can be composed of a combination ofthree different quaternary ammonium groups, or one quaternary ammoniumgroup, one phosphonium group, and one arsonium group. A polyanion can becomposed of three different carboxylate groups or a combination ofcarboxylate groups and sulfonate groups.

B5. Counterions

The polyionic liquids of the present invention are generally salts,although they may exist as ions (+3, −3, +4, −4 etc.) in certaincircumstances. Thus, in most instances, each ion has a counterion, onefor each anion or cation. Charge should be preserved in most cases. Inthe case of a polyanionic ionic liquid, cations are required and in thecase of a polycationic ionic liquid, anions are required. The choice ofanion can have an effect of the properties of the resulting compound andits utility as a solvent. And, while anions and cations will bedescribed in the context of a single species used, it is possible to usea mixture of cations to form salts with a polyanionic species to form apolyanionic ionic liquid. The reverse is true for polycations. Forclarity sake, the salt-forming ions will be referred to as counterionsherein.

The polyon of Formulas I-V form a polyionic salt with counterions havinga charge which is opposite to that of the A substituent.

In some embodiments, the counterions are cationic.

Cationic counterions can include any of the polycationic compoundspreviously identified for use in the production of polycationic ionicliquids. In addition, monoionic counterparts of these may be used. Thus,for example, quaternary ammonium, protonated tertiary amine,phosphonium, and arsonium groups are useful as cationic counterions forpolyanionic molecules to form polyanionic ionic liquids in accordancewith the present invention.

When A is anionic, the counterions are cationic which, withoutlimitation, include a quaternary ammonium, a protonated tertiary amine,a phosphonium or an arsonium group.

In other embodiments, the counterions are anionic.

Anionic counterions can be selected from any of the polyanionicmolecules discussed herein useful in the creation of polyanionic ionicliquids. These would include dicarboxylates, disulfonates anddisulfates. The corresponding monoionic compounds may also be usedincluding carboxylates, sulfonates, sulfates and phosphonates. Halogenand halogen-containing compounds that may be used include, withoutlimitation, triflate, NTf₂ ⁻, PF₆ ⁻, BF₄ ⁻ and the like. The counterionsshould be selected such that the polyionic liquids have good thermaland/or chemical stability and have a solid/liquid transformationtemperature and/or a liquid range as described herein. Finally, theionic groups of the present invention can be substituted orunsubstituted. They may be substituted with halogens, with alkoxygroups, with aliphatic, aromatic or cyclic groups, withnitrogen-containing species, with silicon-containing species, withoxygen-containing species, and with sulphur-containing species. Thedegree of substitution and the selection of substituents can influencethe properties of the resulting material as previously described indiscussing the nature of the bridge or chain. Thus, care should be takento ensure that excessive steric hindrance and excessive molecular weightare avoided, that resulting materials do not lose their overallflexibility and that nothing will interfere with the ionic nature of thetwo ionic species.

When A is cationic, the counterions are anions which, withoutlimitation, include halogens, mono-carboxylates mono-sulfonates,mono-sulfates, NTf₂ ⁻, BF₄ ⁻, trifilates or PF₆ ⁻ as well as moleculeshaving anionic groups each selected from, without limitation,carboxylate, sulfate or sulfonate groups. Other counterions include,without limitation:

wherein R is selected from the group consisting of hydrogen, alkyl,hydroxyalkyl, carbocyclyl, heterocylyl, halo, alkoxy, hydroxyl,alkylcarbonyl, alkylcarbonylalkylene, hydroxycarbonyl,

wherein

X₁ is C₁-C₁₀-alkylene;

X₂ is selected from the group consisting of hydrogen, alkyl, alkoxy,amino and hydroxy;

Y₁ is selected from the group consisting of hydrogen and alkyl; and

Y₂ is C₁-C₁₀-alkylene.

Counterions can be monoionic, diionic or polyionic ions, or a mixturethereof. They can be the same or different so long as they all have thesame type of charge (positive or negative) and the total charge is m.For example, a polyionic liquid can be a mixture of a polycationicliquid and a polyaninoic liquid.

The counterions useful for each monoionic group of NCGPs are the same asthose which may be used in connection with CGPs as previously defined.

B6. Gc Central Groups

Gc is a central group (also referred to as a center or central moiety)that may be substituted or unsubstituted, saturated or unsaturated,aliphatic, including straight or branched chains, cyclic or aromatic,and which may contain, in addition to, or even instead, of carbon atomsand hydrogen, N, P, As, O, S and Si atoms. In CGPs, the central group isnot a charged (ionic) group.

In some embodiments, Gc is phenyl.

In some embodiments, Gc is cycloalkyl.

In some embodiments, Gc is C.

In some embodiments, Gc is Si.

In some embodiments, Gc is N.

In some embodiments, Gc is P.

The central group (Gc in Formula (I) and (II)) or center interposedamong the ionic species can be of any length or any composition whichaffords a polyionic liquid salt of suitable properties. These includethe groups identified as Gc above. There are certain factors that shouldbe considered in selecting such a central moiety. First, the larger thepolyionic molecule in general, the greater the chance that the meltingpoint or temperature of solid/liquid transformation will be elevated.This may be less of a concern where the liquid range need not beextensive and/or where the temperature of solid/liquid transformationneed not be very low. If, however, as is often the case, one desires aliquid range of about 200° C. or higher and/or a solid/liquidtransformation temperature at 100° C. or lower, the size of the overallmolecule can become a larger and larger factor. On the other hand, alarger mass might be good for certain mass spectrometry applications.Second, in some embodiments, it is preferable that the central grouphave some flexibility. In such embodiments, a linear molecule, usuallysaturated, or a cyclic or polycyclic group of limited unsaturation canbe used as the central group. In some other embodiments, a more rigidpolyionic molecule may be desirable. In such embodiments, a high degreeof unsaturated groups, very rigid and/or stericly bulky groups, such asthose found in, for example, cholesterol, and polyunsaturated aliphaticgroups with extensive unsaturation, acryl groups, and cyclic groupsincluding multiple fused ring structures, can be used as the centergroup. In still another embodiment, the central group can be a singleatom such as C, Si, N and P.

The central group may be aliphatic, cyclic, or aromatic, or a mixturethereof. It may contain saturated or unsaturated carbon atoms or amixture of same with, for example, alkoxy groups (ethoxy, propoxy,isopropoxy, butoxy, and the like). It may also include or be madecompletely from alkoxy groups, glycerides, glycerols and glycols. Thecentral group may contain hetero-atoms such as O, N, S or Si andderivatives such as siloxanes, non-protonated tertiary amines and thelike. The central group may be made from one or more cyclic or aromaticgroups such as a cyclohexane, an immidazole, a benzene, a diphenol, atoluene, or a xylene group or from more complex ring-containing groupssuch as a bisphenol or a benzidine. These are merely representative andare not meant to be limiting. Generally, however, the central group willnot contain an ionically charged species, other than the polyanions orpolycations. And, it is possible to make mixtures of PILS each having,for example, the same cationic species, and each having the samecounterions, but differing in the central groups alone. Other variationsare also contemplated.

In some embodiments, the invention provides a polyionic liquid salt inwhich the central group is a linear central group having lengths rangingfrom a length equivalent to that of a saturated aliphatic carbon chainof between about 2 and about 40 carbon atoms (e.g., n=C₂-C₄₀ whencentral group is composed of carbon). Such a polyionic liquid salt istermed a linear-Gc-based polyionic liquid salt. More preferably, thelength should be approximately that resulting from a saturated aliphaticcarbon chain of about 3 to about 30 carbon atoms in length.

In some other embodiments, the invention provides a polyionic liquidsalt in which the central group is a cyclic central group having atleast a three member ring. Such a polyionic liquid salt is termed acyclic-Gc-based polyionic liquid salt. In embodiments involving a cycliccentral group, the number of carbons and/or any heteroatoms in thecentral group can be between 3 and about 40 (e.g., n=C₃-C₄₀ when centralgroup is composed of carbon). More preferably, the number of carbonsand/or any heteroatoms in the central group can be between 5 to about30. The cyclic central group can have, but are not limited to a 3, 4, 5,6 or 7-membered ring. The cyclic central group can also have a fusedmultiple ring.

The cyclic central group can be an alicyclic group containing one ormore all-carbon rings which may be either saturated or unsaturated,either substituted or unsubstituted. Exemplary alicyclic groups include,but are not limited to, cycloalkanes, such as cyclopropane, cyclobutaneand cyclohexane, cycloheptane, bicyclic alkanes, such as norbornene andnorbornadiene, and polycyclic cycloalkane, such as Decalin, Spirogroups, which have bicyclic connected through one carbon atom,cycloalkenes are cyclobutene, cyclopropene and cyclohexene.

The cyclic central group can be an aromatic group containing one or moreall-carbon rings which may be either substituted or unsubstituted.Exemplary aromatic groups include, but are not limited to, benzene,naphthalene, anthracene, benzo[a]pyrene, benzo[ghi]pyrene, chrysene,coronene, fluoranthene, tetracene, pentacene, phenanthrene, pyrene andtriphenylene.

The cyclic central group can be a heterocyclic group that contains atomsin addition to carbon, such as sulfur, oxygen or nitrogen, as part ofthe ring. The heterocyclic groups can be either saturated orunsaturated, either substituted or unsubstituted, either aromatic ornon-aromatic, single or fused. The heterocyclic groups can have, but arenot limited to, 3, 4, 5, 6 or 7 membered rings.

The cyclic groups can also have fused multiple rings. Examples of fusedmultiple rings include, but are not limited to, benzocyclobutene,pentalene, benzofuran, isobenzofuran, indole, isoindole, benzothiophene,benzo[c]thiophene, benzimidazole, purine, indazole, benzoxazole,benzisoxazole, benzothiazole, naphthalene, anthracene, quinoline,isoquinoline, quinoxaline, acridine, quinazoline and cinnoline.

In embodiments in which the central group comprises a mixture of alinear and a cyclic group, the mono-onic groups can be distributedacross the central group in any manner. For example, some of themonoionic groups, A, are conjugated to the cyclic portion while othermonoionic groups are conjugated to the linear portion of the centralgroup.

Gc can be optionally substituted with one or more Rc substituentsindependently selected from the group consisting of a proton,substituted or unsubstituted, saturated or unsaturated, straight orbranched aliphatic chain (such as alkyl), cyclic group (such ascycloalkyl), aromatic group (such of phenyl or substituted phenyl),halo, alkoxy or hydroxyl.

B7. B Substituents

Each B is a bridging group.

Each B may, where present, be the same or different.

In some embodiments, each B is selected from the group consisting ofalkylene, alkenylene, alkynylene, (—CH₂—O—CH₂—),(—CH₂-carbocyclyl-CH₂—)_(n), and polysiloxyl; wherein alkylene,alkenylene, and alkynylene optionally contain one or more heteroatomsselected from the group consisting of O, N, S or Si;

In other such embodiments, B is optionally substituted with one or moresubstituents selected from the group consisting of alkyl, alkenyl,alkyl, and alkoxy.

C. EMBODIMENTS OF POLYIONIC SPECIES OF FORMULAS I-VI

Various embodiments of substituents A, Gc, Rc, R_(A), R₁, R₂, R₃, andR_(n), have been discussed above. These substituent embodiments can becombined to form various embodiments of species of Formulas I-V. Allembodiments of species of Formulas I-V formed by combining thesubstituents embodiments discussed above are within the scope of theinvention.

Examples of such embodiments are shown below as non-limiting formulas.

C1. Triionic Species (Gc=Phenyl)

In some embodiments, Gc is phenyl, substituted with three R_(c) groupsand m is 3. In these embodiments, the species of Formula II correspondin structure to Formulas IIA-IIC.

wherein each A and R_(c) can be the same or different and are as definedabove.

In some such embodiments, at least one R₁ is alkyl. In some suchembodiments, at least two R_(c), are alkyl. In some such embodiments,all three R_(c), are alkyl. Examples of alkyl groups include methyl,ethyl, propyl, butyl and pentyl.

In some such embodiments, R_(c) is alkyl and A is imidazolium. Examplesof such triionic liquid salts are provided, without limitation inTable 1. Each of the above tricationic liquid salts has a melting pointat about −10 to −20° C.

In some embodiments, all three Rc groups are hydrogen. In some suchembodiments, A is imidazolium. Examples of such unsubstitutedphenyl-based triionic liquid salts having imidazoliums are provided,without limitation in Table 2.

Formula IIA

In some embodiments, the species of Formula II correspond in structureto Formula IIA:

wherein each A is identical and as defined above.

In some such embodiments, all A groups are identical.

In some such embodiments, the A groups are selected from the groupconsisting of imidazolium, ammonium, phosphonium, pyridinium andpyrrolidinium.

In some such embodiments, A is imidazolium. In some such embodiments,the species of Formula IIA correspond in structure to the followingformula:

wherein each Rc, R₁, R_(n) and the anion are as defined previously.

In some such embodiments, A is ammonium. In some such embodiments, thespecies of Formula IIA correspond in structure to the following formula:

wherein each Rc, R₁, R₂, R₃, R_(n) and the anion are as definedpreviously.

In another embodiment, a polyionic liquid salt comprises an opticallyactive tricationic species having ammoniums substituted with at leastone alkyl group having one or more chiral centers. In some suchembodiments, the species of Formula IIA correspond in structure to thefollowing formula:

wherein each Ra and Rc and the anion are as defined previously. Theabove described chiral triionic species can be synthesized by proceduresdescribed in Example 10.

In another embodiment, a polyionic liquid salt comprises an opticallyactive tricationic species having ammoniums substituted with arylcontaining groups having one or more chiral centers. In some suchembodiments, the species of Formula IIA correspond in structure to thefollowing formula:

wherein each Rc and the anion are as defined previously. The abovedescribed chiral triionic species can be synthesized by proceduresdescribed in Example 11.

In some such embodiments, A is phosphonium. In some such embodiments,the species of Formula IIA correspond in structure to the followingformula:

wherein each Rc, R₁, R₂, R₃ and the anion are as defined previously.

In some such embodiments, at least one A is phosphonium. In some suchembodiments, the species of Formula IIA correspond in structure to thefollowing formula:

wherein each R_(c) is as defined previously.

The above described central phenyl group-based triionic species can besynthesized by procedures described in Examples 1 and 2. Note that it isalso possible to bond one or more additional groups to one or more ofthe ring carbons illustrated above as being substituted with hydrogenonly.

Examples of phenyl-based triionic species containing phosphoniums areprovided, without limitation in Table 4.

In some such embodiments, A is pyridinium. In some such embodiments, thespecies of Formula IIA correspond in structure to the following formula:

wherein each Rc, and R_(n) and the anion are as defined previously.

In all of the Formula II embodiments listed herein, if any R₁, R₂, R₃,R_(n), or Rc groups are different, for example, R₁ is Br in one groupand Cl in two groups in the above molecule, it would no longer besymmetric. If one of the three R_(c) groups in the figure immediatelyabove are different from the others, but all of the R_(n) groups are thesame, the triion would be neither symmetric nor center-symmetric, but itwould still be an embodiment of the invention.

In some such embodiments, A is pyrrolidinium. In some such embodiments,the species of Formula IIA correspond in structure to the followingformula:

wherein each Rc and R_(n) and the anion are as defined previously.

In some such embodiments, at least one A is pyrrolidinium. In some suchembodiments, all three A groups are pyrrolidium. In some suchembodiments, the species of Formula IIA correspond in structure to thefollowing formula:

wherein each Rc is as defined above.

An example of such a triionic liquid salt is provided, withoutlimitation in Table 3.

In some embodiments, a polyionic liquid salt comprises an opticallyactive tricationic species having pyrrolidiniums with one or more chiralcenters. In some such embodiments, the species of Formula IIA correspondin structure to the following formula:

wherein each R_(c) and the counteranion are as defined previously. (R)-or (S)- is marked by an asterisk (*). The above described chiraltriionic species can be synthesized by procedures described in Example9.

An appropriate counteranion can be selected from those defined above.

In some embodiments, the triionic species comprises three different Agroups.

In some embodiments, a first A is a quaternary ammonium or a protonatedtertiary amine, while a second A is an imidazolium (IM) or a substitutedIM, and a third A is a pyridinium or a substituted pyridinium.

In some embodiments, the A groups are selected from imidazolium,ammonium and phosphonium. In some such embodiments, the species ofFormula IIA correspond in structure to the following formula:

wherein each Rc, R, R₁, R₂, R₃, and R_(n), and the anion are as definedpreviously.

In some such embodiments, the species of Formula IIA correspond instructure to the following formula:

wherein each Rc is as defined previously.

Formula IIB

In some embodiments, the polyionic liquid salt comprises a symmetrictriionic species of the formula IIB:

wherein each A is identical and as defined above.

In some such embodiments, the A groups are identical.

In some such embodiments, the A groups are selected from the groupconsisting of imidazolium, ammonium, phosphonium, pyridinium andpyrrolidinium.

In some such embodiments, A is imidazolium. In some such embodiments,the species of Formula IIB correspond in structure to the followingformula:

wherein R₁, R_(n) and the anion are as defined previously.

In some such embodiments, A is ammonium. In some such embodiments, thespecies of Formula IIB correspond in structure to the following formula:

wherein R₁, R₂, R₃, and the anion are as defined previously.

In some such embodiments, A is phosphonium. In some such embodiments,the species of Formula IIB correspond in structure to the followingformula:

wherein R₁, R₂, R₃, and the anion are as defined previously.

In some such embodiments, A is pyridinium. In some such embodiments, thespecies of Formula IIB correspond in structure to the following formula:

wherein R_(n), and the anion are as defined previously.

In some such embodiments, A is pyrrolidinium. In some such embodiments,the species of Formula IIB correspond in structure to the followingformula:

wherein R_(n), and the anion are as defined previously.

The above described C2 symmetric central phenyl-based triionic speciescan be synthesized by procedures described in Example 12. Note that itis also possible to bond one or more additional groups to one or more ofthe ring carbons illustrated above as being substituted with hydrogenonly.

Formula IIC

In some embodiments, the Gc is unsymmetric such that the polyionicspecies does not possess symmetry along the ionic groups.

For example, in some embodiments, the A groups are conjugated to Gc insuch a manner that the species do not possess symmetry among the ionicgroups. In some such embodiments, the A groups are conjugated to thecarbon 1, 2, and 4 of the ring.

In some such embodiments, the polyionic liquid salt comprises asymmetric triionic species of the formula:

wherein each A is identical and as defined above.

In some such embodiments, the A groups are not all the same.

In other such embodiments, each A is the same monoionic group. Examplesof such species of Formula IIC correspond in structure to the followingformulas:

wherein R₁, R₂, R₃ and R_(n) and the anion are as defined previously.The above described unsymmetric central phenyl-based triionic speciescan be synthesized by procedures described in Example 13.

C2. Tetraionic Species (Gc=Phenyl)

In some embodiments, the polyionic liquid salt comprises a tetraionicspecies wherein m is 4.

In some embodiments, the polyionic liquid salt comprises a tetraionicspecies wherein Gc is phenyl optionally substituted with one or more Rcsubstituents and m is 4.

In some such embodiments, the tetraionic species corresponds instructure to Formulas VIA-VIC:

wherein each A is as defined above.

An example of a polyionic liquid salt is provided, without limitation inTable 5.

The above described central phenyl-based tetraionic species can besynthesized by procedures described in Example 14.

In some embodiments, the tetraionic species corresponds in structure toFormula VID:

wherein each A is as defined previously.

In some such embodiments, z is selected from the group consisting of 1to 20, inclusive.

In some embodiments, at least one R_(c) is alkyl. In some suchembodiments, at two R_(c), groups are alkyl. In other such embodiments,three R_(c), groups are alkyl. In yet other such embodiments, all fourR_(c), groups are alkyl.

In some such embodiments, the species of Formula VID correspond instructure to the formula:

The above described central pyrrole-based tetraionic species can besynthesized by procedures described in Example 15.

C2. Triionic Species (Gc=Cycloalkyl)

In some embodiments, the polyionic liquid salt comprises a triionicspecies, wherein Gc is cycloalkyl substituted with one or more Rcsubstituents, which are as defined previously.

In some such embodiments, the three A monoionic groups are identical.

In some such embodiments, Ge is cyclohexane optionally substituted withone more more Rc substituents.

In some embodiments, the monoionic A group is an imidazolium, ammonium,phosphonium, pyridinium or pyrrolidinium, and Gc is a cyclohexane orsubstituted cyclohexane.

In some such embodiments, the central cyclohexane-based tricationic saltis constructed using 1,3,5-trisubstituted cyclohexanes which have beenproven useful as scaffolds for molecular architectures.

In some embodiments, the polyionic species corresponds in structure to:

wherein each R_(c), can be any of the R_(c) groups defined previously,and A is a monoionic group as defined previously. In addition,cyclohexane containing substitutions at 2, 4, and 6 carbon with any ofthe groups defined previously are also contemplated.

In some embodiments, the species of Formula II corresponds in structureto Formula IID:

wherein each R_(c) and A are as defined above.

In some embodiments, the species of Formula II corresponds in structureto Formula IIE:

wherein each R_(c) and A are as defined above.

In some embodiments, the species of Formula IIE correspond in structureto the following:

wherein Rc, R₁, R₂, R₃, R_(n) and the anion are as defined previously.The above described central cyclohexane-based triionic species can besynthesized by procedures described in Examples 3 and 4. Note that it isalso possible to bond one or more additional groups to one or more ofthe ring carbons illustrated above as being substituted with H only.Examples of a triionic liquid salt comprising such centralcyclohexane-based tricationic species are provided, without limitationin Table 6.

C3. Triionic Species (Gc=C or Si)

In some embodiments, the polyionic liquid comprises a triionic species,wherein Gc is selected from the group consisting of C and Si. Suchspecies are termed C-Gc-based or Si-Gc-based triionic species.

In some such embodiments, the three A groups are identical and aspreviously defined.

In some embodiments, the species of Formula II corresponds in structureto the C-Gc-based triionic species of Formula IIF:

wherein each A is as defined above.

In some such embodiments, A is selected from the group consisting ofimidazolium, ammonium, phosphonium, pyridinium and pyrrolidinium. Insome such embodiments, the species of Formula IIF correspond instructure to:

wherein R₁, R₂, R₃, R_(n), and the anion are as defined previously. Theabove described central carbon-based triionic species can be synthesizedby procedures described in Examples 5 and 6. Note that the presence ofthe methyl group (—CH₃) means that the above triions are neithersymmetric nor center-symmetric. Examples of a polyionic liquid saltcomprising such C-Gc-based triionic species are provided, withoutlimitation in Table 7.

C4. Triionic Species (Gc=N or P)

In some embodiments, the polyionic liquid comprises a triionic species,wherein Gc is selected from the group consisting of N and P. Suchspecies are termed N-Gc-based or P-Gc-based triionic species.

In some embodiments, Gc is P.

In some embodiments, Gc is N.

In some such embodiments, all three A groups are identical and can beany monoionic group previously defined.

In some embodiments, the species of Formula II corresponds in structureto the N-Gc-based triionic species of Formula IIG:

In some embodiments, the species of Formula II correspond in structureto Formula IIG:

wherein each A is as defined above.

In some such embodiments, the A groups are identical.

In some such embodiments, the monoionic A group selected from the groupconsisting of imidazolium, ammonium, phosphonium and pyridinium.

In some such embodiments, the species of Formula IIG correspond instructure to:

wherein R₁, R₂, R₃, R_(n) and the anion are as defined previously. Theabove described central carbon-based triionic species can be synthesizedby procedures described in Examples 7 and 8. Assuming that all of thesubstitutions on each ion are the same, then these triions would be bothsymmetric and central-symmetric. Examples of such N-Gc-based species areprovided, without limitation in Table 8.

In some embodiments, the species of Formula II correspond in structureto Formula IIH:

wherein each t is independently selected from the group consisting of 1to 20, inclusive; and each A is as defined previously. Examples of suchtriionic species are provided, without limitation in Table 9.

C5. Triionic Species (Gc=Alkyl)

In some embodiments, the species of Formula II correspond in structureto Formula IIJ:

wherein each A is as defined above.

In some such embodiments, A is an anionic group.

In some such embodiments, each A is independently selected from thegroup consisting of carboxylate, sulfonate and sulfate; wherein eachsuch substituent is optionally substituted with one or more substituentsindependently selected from the group consisting of alkyl, carbocyclyland heterocyclyl. Non-limiting examples of such a trianionic species isprovided in Table 10. This trianionic species can be synthesized byprocedures described in Example 16.

In other such embodiments, A is a cationic group. In these embodiments,the cationic group can be any previously defined.

C6. Non-Central Group Species

Exemplary species of Formula III can be synthesized by proceduresdescribed in Examples 17 and 18. Non-limiting examples of such triionicNCGP species are provided in Table 11.

In some embodiments, the species of Formula V correspond in structure toone of the following formulas:

wherein each v is independently selected from the group consisting of1-20, inclusive.

The species of Formula V can be synthesized by procedures described inExample 19. A cyclized version is also possible where the two freequaternary groups are joined to complete a ring.

C7. Species Examples

Examples of species of Formulas I-VI are shown in Tables 1-11 below. Thesynthesis examples below provide step-by-step preparation instructionsfor some of these species.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

TABLE 7

TABLE 8

TABLE 9

TABLE 10

TABLE 11

C. POLYIONIC LIQUID SALTS AS SOLVENTS

This invention is also directed to solvents comprising one or morepolyionic liquid salts in accordance with the invention.

In some embodiments, the solvent comprises one polyionic liquid salt.

In other embodiments, the solvent comprises more than one polyionicliquid salt.

The polyionic liquid salts of the present invention can be used in pureor in substantially pure form as carriers or as solvents.“Substantially” in this context means no more than about 10% ofundesirable impurities. Such impurities can be other undesired polyionicsalts, reaction by-products, contaminants or the like as the contextsuggests. In an intended mixture of two or more PILS, neither would beconsidered an impurity. Because they are non-volatile and stable, theycan be recovered and recycled and pose few of the disadvantages ofvolatile organic solvents. Because of their stability over a wide liquidrange, in some instances over 400° C., they can be used in chemicalsynthesis that requires both heating and cooling. Indeed, these solventsmay accommodate all of the multiple reaction steps of certain chemicalsyntheses. Of course, these polyionic liquids may be used in solventsystems with co-solvents and gradient solvents and these solvents caninclude, without limitation, chiral ionic liquids, chiral non-ionicliquids, volatile organic solvents, non-volatile organic solvents,inorganic solvents, water, oils, etc. It is also possible to preparesolutions, suspensions, emulsions, colloids, gels and dispersions usingthe polyionic liquids. Polyionic salts in accordance with the inventionmay be used in any mixture, including different polycations, differentpolyanions and mixtures of polycations and polyanions. In addition, oneor more of the polyionic liquid salts of the invention may be mixed withdiionic liquid salts as described in U.S. Patent Publication No.2006/0025598, the text of which is hereby incorporated by reference.

In addition to discrete polyionic liquid salts, it is also possible toproduce polymers of these materials. Polymers may include the polyionicliquid salts within the backbone or as pendant groups and they may becross-linked or non-cross-linked.

In addition to being useful as solvents and reaction solvents, thepolyionic liquid salts of the present invention can be used to performseparations as, for example, the stationary phase for gas-liquidchromatography. Polyionic liquid salts having unsaturated groups can becross-linked and/or immobilized. For example, polyionic liquid salts canbe coated on a capillary (or solid support) and optionally, subsequentlypolymerized and/or cross-linked.

Indeed, in one aspect of the present invention, there are providedimmobilized ionic liquids including one or more high stability polyionicliquid salts (with or without monoionic materials) as stationary phases,particularly in gas chromatography. These stationary phases are highlyselective, highly stable, and highly resistant to temperaturedegradation. These materials can be non-cross-linked (which often meansthat they are absorbed or adsorbed on a solid support or column), can be“partially” cross-linked or “more highly” cross-linked (which oftenmeans that they are “immobilized” on a solid support or column) and canbe composed of a mixture of polyionic liquid salts and diionic materialand/or monoionic materials or can be made completely of polyionic liquidsalts in accordance with the present invention. In the case ofnon-cross-linked stationary phases, the polyionic salts used may besaturated, unsaturated or a mixture of both. It should be understood,however, particularly if some amount of unsaturated polyionic liquidsalts are used, and especially where heat is used to fix the stationaryphase, or the stationary phase is heated during use, as in GC, somedegree of cross-linking is possible. “Partially” cross-linked stationaryphases in accordance with the present invention permit production of amore stable, highly selective stationary phase, allowing for highefficiency separations at temperatures up to approximately 280° C. In“partially cross-linked” stationary phases, there can be a mixture ofmono and polyionic species and the amount of polyionic liquid salts usedwill be equal to or less than the amount of monoionic species used.“More highly” cross-linked stationary phases in accordance with thepresent invention can provide superior efficiency and stability even attemperatures up to 35° C. and higher. In “more highly cross-linked”stationary phases, the amount of polyionic species (polyionicliquids/salts) will surpass that of any monoionic species. Indeed,preferably, more highly cross-linked stationary phases will be composedsubstantially exclusively (90% or more) of immobilized polyionic liquidsalts in accordance with the invention. Indeed, they are preferablypurely polyionic liquid salts. In either case, the monoionic species,diionic species and the polyionic species used preferably includeunsaturation. The monoionic species will generally have a singlemultiple bond, the diionic liquid salts will generally have two or moremultiple bonds (double bonds/triple bonds), while the polyionic liquidsalts will generally have three or more multiple bonds (doublebonds/triple bonds). Of course, the polyionic or diionic species canhave but a single unsaturated bond as well. These unsaturated bonds notonly allow cross-linking, but also facilitate immobilization. Mixturesof saturated and unsaturated species may also be used, particularly inthe case of non-cross-linked stationary phases.

In a particular embodiment, the stationary phases are made from apolyionic species which is chiral and optically enhanced. Moreover,cross-linking and/or immobilization of the ionic liquids in a column asa stationary phase, or to a solid support for SPE, SPME, task-specificSPE or SPME, SPME/MALDI, ion exchange and headspace analysis or otheranalytical or separation technique, does not appear to affect theselectivity of the stationary phase, thereby preserving its dual natureretention behavior.

And while stationary phases for gas chromatography and in particularcapillary GC are one particular aspect of the present invention, thepolyionic liquid salts, either alone or in combination with monoionicliquid salts and/or diionic liquid salts, can be used as a stationaryphase in other forms of chromatography including, for example, liquidchromatography (“LC”) and high performance liquid chromatography(“HPLC”). Not only are the methods of creating stationary phases, solidsupports and/or columns containing same contemplated, the stationaryphases, solid supports and columns themselves and the use of columns andsolid supports containing these stationary phases in chromatography,another analytical or separation techniques are contemplated as specificaspects of the invention.

Thus, one or more polyionic liquid salts in accordance with the presentinvention can be used in analytical and separation technologies otherthan chromatography, all of which are considered as part of the presentapplication. For example, polyionic liquid salts in accordance with thepresent invention can be used in, without limitation, solid phaseextraction (“SPE”), solid phase microextraction (“SPME”), task-specificSPME (“TSSPME”), and certain types of mass spectrometry known as solidphase microextraction/MALDI, as well as ion exchange and headspaceanalysis. The invention includes not only the use of ionic liquid saltsand, in particular, polyionic liquid salts in these techniques, but alsosolid supports to which ionic liquid salts, and in particular, polyionicliquid salts, are absorbed, adsorbed or immobilized as well as samplingdevices such as, for example, pipettes, automatic pipettes, syringes,microsyringes and the like incorporating ionic liquid salts, such aspolyionic liquid salts, which can be used in such analytical andseparation techniques. Solid supports include, without limitation, mixedbeds of particles coated with ionic liquid salts. These may be used aschromatographic media or for SPE, SPME, SPME/MALDI and ion exchangeanalysis. Particles may be composed of, for example, silica, carbons,composite particles, metal particles (zirconia, titania, etc.), as wellas functionalized particles, etc. contained in, for example, tubes,pipettes tips, needles, vials, and other common containers.

In yet another embodiment, the present invention provides a polyionicliquid salt (“liquid” meaning liquid salts at either room temperature(25° C.) or at a temperature above the solid/liquid transformationtemperature, which may be 400° C. or lower, unless otherwise indicated)having a solid/liquid transformation temperature which is about 40° C.or lower, said polyionic liquid salt including two monoionic groupsseparated by a bridging group and either two monoionic counterions or atleast one polyionic counterion. In one embodiment, the two monoionicgroups are both cationic or anionic and in another embodiment, they aregerminal (the same). When cationic, it is preferred that the groups arequaternary ammonium, protonated tertiary amine, thionium, phosphonium orarsonium groups which may be substituted or unsubstituted, saturated orunsaturated, linear, branched, cyclic or aromatic. When anionic, thegroups are preferably carboxylate, sulfate or sulfonate groups which maybe substituted or unsubstituted, saturated or unsaturated, linear,branched, cyclic or aromatic. In a particular embodiment, thesepolyionic liquid salts include at least one unsaturated bond which canfacilitate cross-linking and/or immobilization.

In another embodiment, one or more polyionic liquid salts can be used asa solvent for dissolution, suspension or dispersion of solids or liquidmixed therewith or as a reaction solvent for chemical reactions. Bothare intended by the term solvent. In a particular embodiment, a solventcomprises: one or more polyionic liquid salts as noted above having asolid/liquid transition temperature of about 50° C. or lower, morepreferably about 40° C. or lower and having a liquid range of about 20°C. or higher; and, in another embodiment, stability is measured by beingsubstantially non-volatile at a temperature of about 20° C. or below.Both polyionic liquid salts and the solvents made therefrom may bechiral and optically enhanced.

D. DEVICES

This invention is also directed, in part, to a device for chemicalseparation or analysis comprising a solid support and one or morepolyionic liquid salts of the invention which is adsorbed, absorbed orimmobilized on the solid support. In a particular embodiment, a deviceof the invention comprises a syringe, a hollow needle, a plunger, andthe solid support being attached to the syringe.

Another embodiment of the present invention is a device useful inchemical separation or analysis comprising: a solid support and one ormore polyionic liquid salts as described above adsorbed, absorbed orimmobilized thereon. The device may be a column used in HPLC, GC orsupercritical fluid chromatography (SFC) wherein the solid support ispacked in a chromatographic column or wherein the solid support is acapillary column useful in gas chromatography.

The device may also be a syringe having a hollow needle defining aninner space, the needle being disposed at an end of a barrel and aplunger disposed within the barrel, the solid support being attached,mounted or affixed, irremovable or removable, (collectively “attached”)to the syringe such that it may be retracted into the inner space of theneedle when the plunger is retracted from the barrel and exposed fromwithin the needle when the plunger is inserted into the barrel. In oneembodiment, the syringe is a microsyringe. In some embodiments, the oneor more polyionic liquid salts used in these devices also includemonoionic materials and/or diionic materials which may be simply mixedtherewith or which may be cross-liked to the polyionic liquid salts ofthe invention. These may be absorbed, adsorbed or immobilized on thesolid support. When immobilized, it is preferred that these ionicspecies include unsaturated groups.

E. Methods of Use.

This invention also is directed, in part, to a method of using one ormore polyionic liquid salts of the invention in analytical andseparation technologies such as, but not limited too, liquidchromatography (“LC”), high performance liquid chromatography (“HPLC”),solid phase extraction (“SPE”), solid phase microextraction (“SPME”),task-specific SPME (“TSSPME”), and mass spectrometry known as solidphase microextraction/MALDI, as well as ion exchange and headspaceanalysis.

In one other embodiment, there is provided a method of separating onechemical from a mixture of chemicals comprising the steps of providing amixture of at least one first and at least one second chemical, exposingthat mixture to at least one solid support including one or morepolyionic liquid salts as described above using a device as describedabove and retaining at least a portion of the first chemical on thesolid support for some period of time. “Retaining” in this context doesnot mean permanently. Separation can occur in a syringe device byremoval of the device from the sample or ejection of the secondchemical. In the case of a chromatography column, the first chemicalwill be absorbed or adsorbed at a different rate than the secondchemical, which may be at a greater rate or a lower rate, thus resultingin separation. Both are moved through the column by a mobile phase,which can be a liquid or a gas and their interaction with the stationaryphase (the ionic liquid materials on the solid support) at differentrates causes separation. This is what is meant by “retention” in thecontext of chromatography. However, in certain types of chromatography,it is also possible that the first chemical is bound to the stationaryphase while the second chemical is not and is carried through the columnby the mobile phase until it elutes. The first chemical can be eluted orremoved separately and this is also embraced by the word “retained.”

The ionic liquid can be coated via the static coating method at 40° C.using coating solution concentrations ranging from 0.15-0.45% (w/w)using solutions of methylene chloride, acetone, ethyl acetate, pentane,chloroform, methanol or mixtures thereof. After coating of the ionicliquid is complete, the column is purged with helium and baked up to100° C. The efficiency of naphthalene (other molecules such asn-hydrocarbons or Grob Test Mixture can also be used for this purpose)is then evaluated to examine the coating efficiency of the monomer ionicliquid stationary phase. If efficiency is deemed sufficient, the columnis then flushed with vapors of azo-tert-butane, a free radicalinitiator, at room temperature. After flushing with the vapors, thecolumn is then fused at both ends and heated in an oven using atemperature gradient up to 200° C. for 5 hours. The column is graduallycooled and then re-opened at both ends, and purged with helium gas.After purging with helium gas overnight, the column is then heated andconditioned up to 200° C. After conditioning, the column efficiency isthen examined using naphthalene at 100° C. and the stationary phasecoated layer examined under a microscope. Note that the cross linkingprocess can, and often does, also cause immobilization. “Immobilized” inthe context of the invention means covalently or ionically bound to asupport or to another ionic liquid (including polyionic liquid salts) orboth. This is to be compared with ionic liquids which may be absorbed oradsorbed on a solid support. Solid support in these particular instanceswas intended to include columns (e.g., the walls of the columns).

It is not necessary, however, to cross-link these materials prior totheir use in GC. They may be adsorbed or absorbed in a column, or indeedon any solid support. However, at higher temperatures, their viscositymay decrease and they can, in some instances, flow and collect asdroplets which can change the characteristics of the column.Immobilization or partial cross-linking also reduces the vapor pressureof the stationary phase film which translates into lower column bleedthereby increasing the useful upper temperature limit of the phase andcolumn.

Another method involves adding up to 2% of the monomer weight of2,2′-azobisisobutyronitrile (“AIBN”) free radical initiator to thecoating solution of the monomer. The capillary column is then filledwith this solution and coated via the static coating method. Aftercoating, the capillary column is then sealed at both ends and placed inan oven and conditioned up to 200° C. for 5 hours. The column isgradually cooled and then reopened at both ends, and purged with heliumgas. After purging with helium gas overnight, the column is then heatedand conditioned up to 200° C. After conditioning, the column efficiencyis then examined using naphthalene at 100° C. and the stationary phasecoated layer examined under a microscope.

In addition to the free radical polymerization of an alkene, otherpolymerization reactions involving other functional groups eitherattached to the aromatic ring of the cation, the linkage chainconnecting two cations (to form a dication), or the anion can beachieved. Examples of such reactions may include cationic and anionicchain growth polymerization reactions, Ziegler-Natta catalyticpolymerization, and step-reaction polymerization. The use of twodifferent monomers to form copolymers through addition and blockcopolymerization can also be achieved. Additionally, condensationpolymerization can be used to connect through functional groups such asamines and alcohols. All polymerization and cross-linking reactionsdiscussed in the following 2 references can be used: “ComprehensivePolymer Science—The Synthesis, Characterization, Reactions andApplications of Polymers” by Sir Geoffrey Allen, FRS; and “ComprehensiveOrganic Transformations: a guide to functional group preparations” byRichard C. Larock. 2nd Edition. Wiley-VCH, New York. Copyright, 1999.

In accordance with another aspect of the present invention, there isprovided a process which includes the free radical reaction of ionicliquid monomers to provide a more durable and robust stationary phase,as well as the cross-linked and/or immobilized stationary phases and thecolumns that include same. By partially cross-linking the ionic liquidstationary phase using a small percentage of free radical initiator,high efficiency capillary columns are produced that are able to endurehigh temperatures with little column bleed. It was found that low tomoderate temperature separations (30° C.-280° C.) can be carried outwith high selectivity and efficiency using special partiallycross-linked ionic liquid stationary phase mixtures. These stationaryphases retain their “gelatinous,” “semi liquid,” amorphous state. Forseparations conducted at higher temperatures (300° C.-400° C.), morehighly cross-linked/immobilized stationary phases are well-suited toprovide high selectivity and efficient separations with low columnbleed. The effect of different functionalized ionic liquid salt mixturesand initiator concentrations is studied for these two types ofstationary phases. The accomplished goal is to maximize their separationefficiency, thermal stability, and column lifetime, without sacrificingthe unique selectivity of the stationary phase.

The following materials can be used to prepare cross-linked stationaryphases comprising polyionic liquid salts in accordance with the presentinvention: 1-vinylimidazole, 1-bromohexane, 1-bromononane,1-bromododecane, 1,9-dibromononane, 1,12-dibromododecane,1-bromo-6-chlorohexane, 1-methylimidazole,N-Lithiotrifluoromethanesulfonimide, 2,2′-Azobisisobutyronitrile (AIBN),dichloromethane and ethyl acetate.

It has been demonstrated previously that room temperature ionic liquidsact as broadly applicable, superb gas chromatographic stationary phasesin that they exhibit a dual nature retention behavior. Consequently,ionic liquid stationary phases have been shown to separate, with highefficiency, both polar and nonpolar molecules on a single column. Byproducing stationary phases that are either partially or highlycross-linked, it is of interest to ensure that the solvationthermodynamics and solvation interactions inherent to ionic liquids arestill retained by their immobilized analogues.

Of course, ionic liquids and in particular the polyionic liquid salts ofthe present invention can be used in other separation and analyticaltechniques. Their range of applicability is in no way limited tochromatography. One technique in which these materials can be used isSolid Phase Extraction (“SPE”). In SPE, a sample contains an impurity orsome other compound or analyte to be separated, identified and/orquantified. This sample can be placed into a container in whichpolyionic liquid salts of the present invention can be present in, andmore broadly, ionic liquids in an immobilized form. Ionic liquidmaterials can be bound (immobilized) to the walls of the container,adsorbed, or absorbed onto a bead or other structure so as to form abead or other structure which may rest at the bottom of the container orbe packed throughout the container much as a liquid chromatographycolumn can be packed with stationary phase. Alternatively, the ionicliquids and in particular polyionic liquid salts of the presentinvention can be immobilized by cross-linking or an analogousimmobilization reaction as described herein on some sort of other solidsupport such as a bead, particles and/or other chromatographic mediaused in chromatography as described previously. These beads can also beplaced at the bottom of, or can fill a container, much as a packedcolumn used for liquid chromatography. Of course, the solid support canbe any structure placed anywhere within the container.

In a particular embodiment, the container is actually a syringe wherethe ionic liquid and/or polyionic liquid salts are affixed or disposedin one fashion or another at the base of the syringe, much as a filter.When the needle of the syringe is placed in a sample and the plunger iswithdrawn, vacuum is formed drawing the sample up into the barrel of thesyringe. This material would pass through at least one layer of ionicliquid and, in particular, polyionic liquid salts in accordance with thepresent invention, which would bind at least one of the components ofthe liquid. The sample liquid could then be spilled out or the plungerdepressed to eject it, the latter forcing the sample back through theionic liquid or polyionic liquid salts positioned at the bottom of thebarrel.

The liquid can be analyzed either for the presence of certain materialsor the absence of the material retained by the ionic liquid or polyionicliquid salts of the present invention. Alternatively, the retainedmaterials can be removed (such as by placing the materials in adifferent solvent) or not and analyzed analytically by other means. Thesame technique may be used in a preparative fashion and/or as a means ofbulk purification as well.

Another technique in which immobilized ionic liquids and polyionicliquid salts of the present invention may be used is solid phasemicroextraction or SPME. Broadly speaking, in these techniques, aseparation material (in this case an ionic liquid or in particular apolyionic liquid salt in accordance with the present invention or ionicliquids mixed with adsorbents, particles and other chromatographicmedia) is absorbed, adsorbed or immobilized in one way or another on afiber (e.g., polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber) orsome other solid support which is applied to the plunger as a coating oras a sheet generally attached to a plunger in a microsyringe such asusually used in gas chromatography. The diionic liquid salts of theinvention can also be immobilized and attached directly without anyseparate solid support other than the plunger. This can be done using,for example, a film directly. In the case of the invention, immobilizedionic liquids and absorbed, adsorbed and immobilized polyionic liquidsalts are contemplated. The plunger is depressed, exposing the fiber andthe fiber is then dipped into the sample of interest. The plunger canthen be withdrawn to pull the fiber back into the barrel of the syringe,or at least the barrel of the needle for protection and transport. Thesyringe can then be injected through the septum of a gas chromatographor some other device and the fiber thereby inserted into the column byredepressing the plunger of the microsyringe. The heat used in GC thenvolatilizes or otherwise drives the bound sample off where it is carriedby the mobile phase through the GC column, allowing for separationand/or identification. It can also be eluted by a liquid mobile phase inan HPLC injector or unbuffer capillary electrophoresis. Immobilizedionic liquids and diionic liquid salts of the present invention may alsobe used in conjunction with the coated stir bar technology, which is ahigher capacity version of SPME. Some embodiments of this coated stirbar technology are sold under the trademark TWISTER.

More specifically, solid phase microextraction is a technique in which asmall amount of extracting phase (in this case an ionic liquid andpreferably a polyionic liquid salt in accordance with the presentinvention) is disposed on a solid support, which was then exposed to asample for a period of time. In situations where the sample is notstirred, a partitioning equilibrium between a sample matrix and theextraction phase is reached. In cases where convection is constant, ashort time pre-equilibrium extraction is realized and the amount ofanalyte extracted is related to time. Quantification can then beperformed based on the timed accumulation of analysis in the coating.These techniques are usually performed using open bed extractionconcepts such as by using coated fibers (e.g., fused silica similar tothat used in capillary GC or capillary electrophoresis, glass fibers,wires, metal or alloy fibers, beads, etc.), vessels, agitation mechanismdiscs and the like. However, in-tube approaches have also beendemonstrated. In-tube approaches require the extracting phase to becoated on the inner wall of the capillary and the sample containing theanalyte of interest is subject to the capillary and the analytes undergopartitioning to the extracting phase. Thus, material can be coated onthe inner wall of a needle, for example, and the needle injected withoutthe need for a separate solid support.

FIG. 1 shows an example of an SPME device 1. A stainless steel microtube40 having an inside diameter slightly larger than the outside diameterof, for example, a fuse silica rod 60 is used. Other inert metals, suchas Nitinol (nickel/titanium alloy) can be also employed in SPME insteadof stainless steel. Typically, the first 5 mm is removed from a 1.5 cmlong fiber, which is then inserted into the microtubing. Hightemperature epoxy glue is used to permanently mount the fiber. Fiberscan also be crimped to the syringe plunger without using adhesives.Sample injection is then very much like standard syringe injection.Movement of the plunger 30 allows exposure of the fiber 60 duringextraction and desorption and its protection in the needle 20 duringstorage and penetration of the septum. 10 shows the barrel of themicrosyringe, 50 shows the extreme end of the stainless steel microtubein which the silicon fiber is mounted.

Another embodiment of a syringe useful for SPME in accordance with thepresent invention is illustrated in FIG. 2. Syringe 2 can be built froma short piece of stainless steel microtubing 130 to hold the fiber.Another piece of larger tubing 120 works as the needle. A septum 110 isused to seal the connection between the microtubing 130 and the needle120. The silica fiber 140 is exposed through one end of the microtubing130 and the other end is blocked by a plunger 100. Withdrawing plunger100 retracts microtubing 130 and the fiber 140 into the barrel of thedevice, the needle 120. Depressing plunger 100 reverses this process.These are but exemplary structures and any syringe device, includingthose containing a needle or tube with the ionic liquid immobilized onthe inner surface thereof, are also contemplated.

In addition, one or more polyionic liquid salts in accordance with thepresent invention can be immobilized by being bound or cross-linked tothemselves and/or to a solid support as previously discussed inconnection with manufacturing capillary GC columns. To do so, however,the species used should have at least one unsaturated group disposed toallow reaction resulting in immobilization.

Another type of SPME technique is known as task specific SPME or TSSPME.Task specific SPME allows for the separation or removal, and thereforethe detection of particular species. These can include, for example,mercury and cadmium, although the technique is equally applicable toother materials. The concept is exactly the same as previously describedwith regard to SPME. However, in this instance, the ionic liquids orpolyionic liquids used are further modified such that they willspecifically interact with a particular species. Those shown below, forexample, may be used in the detection of cadmium (Cd²⁺) and/or mercury(Hg²⁺). The first monocationic material can be coated, absorbed oradsorbed onto a fiber as previously discussed. A polyionic liquid saltcan also be absorbed or adsorbed in known fashion.

Finally, a particular sample can be suspended in a matrix that includesionic liquids and preferably polyionic liquid salts in accordance withthe present invention. This matrix can be loaded or immobilized on thefiber of an SPME syringe as described above and then injected into amass spectrometer to practice a technique known as SPME/MALDI massspectrometry.⁵⁵ The matrix is exposed to a UV laser. This causes thevolatilization or release of the sample much as heat does in a GC. Thisallows the sample to enter mass spectrometer where it can be analyzed.

Polyanionic anions can also be used with either monocations orpolycations to form a variety of different ionic liquid combinations.When a polycation is used, anyone is used as charge balance must bepreserved. The polyanionic anions can be of the dicarboxylic acid type(i.e., succinic acid, nonanedioic acid, dodecanedioic acid, etc).

In a further embodiment, the invention provides a method of detecting acharged molecule using electrospray ionization-mass spectrometry(ESI-MS). The one or more polyionic liquid salts may be used as areagent to detect charged anions in the positive mode by ESI-MS. In themethod, a suitable amount of the polyionic species of the inventionhaving the opposite charges is added to the sample. The charged speciesin the sample to be detected may be, but need not be polyionic as well,e.g., having +2 or −2 charges. The polyionic species and the chargedmolecule form a salt complex. The salt complex is generally a solid. Thepolyionic species contains at least one more opposite charge than thecharged molecule to be detected such that the complex has a net charge.Preferably, the polyionic species contains no more than one oppositecharge than the charged molecule to be detected such that the complexhas a net charge of +1 or −1. However, +2 or −2 or even higher chargedifference can also be used. The complex is then detected using ESI-MS.The formation of the complex converts the charged molecule into an ionhaving a higher mass to charge ratio m/z, which can be transferred byESI more efficiently due to mass discrimination. Benefits of using thepolyionic liquid salts as such reagent include, without limitation, (a)moving anions to a higher mass range out of the low mass regionsdominated by chemical noise, (b) increasing sensitivity for anions withmasses near the low mass cutoff of quadrupole instruments (e.g. traps),and (c) help discriminate against interferences with the same mass tocharge ratio. ESI-MS may be used alone or in combination with aseparation method, such as those discussed above.

In another particular embodiment, the method includes selecting apolyionic species that has a desired composition and structure, e.g., adesired number of charged groups, a desired charged group structure anda desired mass, or a combination thereof. The charged groups in thepolyionic species can be selected based on the composition and structureof the charged molecule to be detected. Preferably, the polyionicspecies is specific for the charged molecule to be detected. Thus, it ispreferable that the charged group of the polyionic species is such thatit binds strongly with the charged molecule to be detected. Morepreferably, the charged group of the polyionic species is such that itdoes not bind strongly with other charged molecules, in the sample.Using a polyionic species that is specific for a charged molecule ofinterest allows high selectivity in detecting the charged molecule. Useof polyionic species having two or more different ionic groups may offerparticular advantages in tailoring the affinities for differentmolecules for detection.

The mass of the polyionic species can be selected to achieve optimaldetection by the mass spectrometer. In general, a polyionic specieshaving a large mass is used. In a particular embodiment, the polyionicspecies is selected such that the complex has a m/z at least 50. Mostcommercial single quadruple mass spectrometers are designed to havetheir optimum performance at m/z values significantly higher than 100.Thus, in another particular embodiment, the polyionic species isselected such that the complex has a m/z significantly higher than 100,e.g., at least about 200, at least about 300, or at least about 400. Aperson skilled in the art will understand that the mass of the polyionicspecies depends on the sizes of the charged groups as well as thebridging group. One or more of these can be varied to obtain a polyionicspecies of desired mass. More preferably, the polyionic species has nomore than one opposite charge than the charged molecule to be detectedsuch that the complex has a net charge of +1 or −1, i.e., z=1. The loweris the value of z; the higher is m/z, which leads to optimum detectionperformance. For example, to detect a −2 charged molecule, a tricationicspecies that forms with the charged molecule a complex having a netcharge of +1 is preferably used.

In a further embodiment, the method includes selecting a polyionicliquid salt that dissociates with high yield. This can be achieved byselecting a polyionic liquid salt containing suitable counterions. Incases where a polyionic liquid salt having desired ionic groups but lessdesirable counterions, it can be converted to a polyionic liquid saltcontaining the desired counterions by ion exchange. In a specificembodiment, a fluoride salt of a cationic species is used as a reagentfor ESI-MS, which, if not available, can be converted from a dihalide, abromide or an iodide salt by anion exchange.

In another embodiment, the method further includes a step of performingion chromatography prior to the addition of the polyionic species.

In a particular embodiment, the invention provides a method of detectinga charged molecule of −2 charge by mass spectrometry, particularlyESI-MS, using a tricationic species of the invention. Any one of thetricationic species described above can be used.

In another particular embodiment, the invention provides a method ofdetecting a charged molecule of +2 charge by mass spectrometry,particularly ESI-MS, using a trianionic species of the invention. Anyone of the trianionic species described above can be used.

In another particular embodiment, the invention provides a method ofdetecting a plurality of different charged molecules by massspectrometry using a plurality of different diionic species of theinvention. Each of the diionic species is selected to specifically bindone of the different charged molecules. Preferably, the differentdiionic species have different masses such that the complexes formedwith their respective charged molecules can be detected separately. Inone embodiment, the plurality of different charged molecules aredifferent charged molecules of +2 or −2, and the plurality of differentpolyionic species are trianionic species or tricationic species,respectively.

Mass spectrometry can be carried out using standard procedures known inthe art.

In another aspect of the present invention, a mixture is providedcomprising at least one polyionic liquid salt of the invention andtraditional stationary phase material such as but not limited topolysiloxanes, PEGs, methylpolysiloxances, phenyl substitutedmethylpolysiloxance, nitrile substituted methylpolysiloxance andcarbowax. Such mixture (mixed stationary phase or “MSP”) can be used asa stationary phase in chromatography such as gas chromatography, liquidchromatography and high performance liquid chromatography as well as inSPE and SPME. Both polycationic liquid salt and polyanionic liquid saltcan be used for this purpose. The MSPs can be non-cross-linked (e.g.,absorbed or adsorbed on a solid support or column), can be “partially”cross-linked or “more highly” cross-linked (i.e., immobilized on a solidsupport or column). The polyionic liquid salt may also be cross-linkedor otherwise reacted with the traditional stationary phase material ormerely mixed therewith.

Thus, in one embodiment, the invention provides MSPs comprising at leastone of the polyionic liquid salts of the invention and at least onetraditional stationary phase material at a suitable proportion.Appropriate combinations of the polyionic liquid salt(s) and thetraditional stationary phase material(s) for producing the MSP is basedon the particular application as are the proportions of the polyionicliquid salt(s) and the traditional stationary phase material(s) in theMSP. In a particular embodiment, the ratio of the polyionic liquid saltand the traditional stationary phase material in the MSP is from about1:9 (i.e., about 10% of polyionic liquid salt and 90% of traditionalstationary phase material) to about 9:1 (i.e., about 90% of polyionicliquid salt and about 10% of traditional stationary phase material),about 1:3 (i.e., about 25% of polyionic liquid salt and about 75% oftraditional stationary phase material) to about 3:1 (i.e., about 75% ofpolyionic liquid salt and about 25% of traditional stationary phasematerial), about 1:2 (i.e., about 33% of polyionic liquid salt and about67% of traditional stationary phase material) to about 2:1 (i.e., about67% of polyionic liquid salt and about 33% of traditional stationaryphase material), or about 1:1 (i.e., about 50% of polyionic liquid saltand about 50% of traditional stationary phase material) (w/w).Chromatography employing MSP may perform better, e.g., having higherselectivity, than chromatography employing polyionic liquid salts or thetraditional stationary phase alone. As an example, an MSP comprising asimple mixture of about 67% (dibutyl imidazolium)₂(CH₂)₉ and about 33%of methylpolysiloxance with about 5% phenyl substitution was preparedand used to coat a column. This MSP was shown to exhibit betterseparation of an essential oil. Cross-linked version of the MSP can alsobe used.

In addition, the invention also provides methods of preparing MSPs,solid supports and/or columns containing same, the MSPs, solid supports,syringes, tubes, pipettes tips, needles, vials, and columns themselves,and the use of columns and solid supports containing such MSPs inchromatography and other analytical or separation techniques such asthose described elsewhere herein.

EXAMPLES

The following examples are merely illustrative, and not limiting to thisdisclosure in any way. The production of polyionic liquid salts isdescribed in Examples 1-19 below.

Example 1 Synthesis of C3 symmetric phenyl and imidazoliumbased-tricationic liquid salt

The ionic compound with bromide was obtained by refluxing1,3,5-tris(bromomethyl)benzene and 1-butylimidazole in 1,4-dioxane. Thecompound with the anion of Tf₂N is a room temperature ionic liquid,which was synthesized by the metathesis reaction of the bromide compoundwith LiNTf₂ (Lithium trifluoromethanesulfonimide) in water.

Example 2 Synthesis of C3 Symmetric Phenyl and Pyrrolidinium-BasedTricationic Liquid Salt

The ionic compound with bromide was obtained by refluxing1,3,5-tris(bromomethyl)benzene and 1-butylpyrrolidine in 1,4-dioxane.The compound with the anion of Tf₂N is a room temperature ionic liquid,which was synthesized by the metathesis reaction of the bromide compoundwith LiNTf₂ (Lithium trifluoromethanesulfonimide) in water.

Following similar synthetic procedures, the phosphonium orpyridium-based ionic liquids of the invention can be obtained.

Example 3 Synthesis of Cyclohexane and Imidazolium-Based TricationicLiquid Salt

The intermediate of 1,3,5-tris(bromomethyl)cyclohexane is synthesized asshown in Scheme 3. Then, the ionic compound with bromide is obtained byrefluxing 1,3,5-tris(bromomethyl)-cyclohexane and 1-butylimidazole in1,4-dioxane. The synthesis of the compound with the anion of NTf₂involves the metathesis reaction of the bromide compound with LiNTf₂.

Example 4 Synthesis of Cyclohexane and Pyrrolidinium-Based TricationicLiquid Salt

For an example, as shown in Scheme 4, the ionic compound with bromide isobtained by refluxing 1,3,5-tris(bromomethyl)cyclohexane and1-butylpyrrolidine in 1,4-dioxane. The compound with the anion of NTf₂is synthesized by the metathesis reaction of the bromide compound withLiNTf₂ in water.

Following similar synthetic procedures, the phosphonium orpyridinium-based ionic liquids of the invention can be obtained.

Example 5 Synthesis of Central Carbon Based-Tricationic Liquid Salt

The ionic compound with chloride is obtained by refluxing thecommercially available 1,3-dichloro-2-(chloromethyl)-2-methylpropane and1-butylimidazole in 1,4-dioxane. The compound with the anion of NTf₂ issynthesized by the metathesis reaction of the chloride compound withLiNTf₂.

Example 6 Synthesis of Central Carbon Based-Tricationic Liquid Salt

The ionic compound with chloride is obtained by refluxing1,3-dichloro-2-(chloromethyl)-2-methylpropane and 1-butylpyrrolidine in1,4-dioxane. The compound with the anion of NTf₂ is synthesized by themetathesis reaction of the chloride compound with LiNTf₂.

Following similar synthetic procedures, the phosphonium orpyrrolidinium-based ionic liquids of the invention can be obtained.

Example 7 Synthesis of Central Nitrogen Based-Tricationic Liquid Salt

The ionic compound with chloride is obtained by refluxing thecommercially available tris(2-chloroethyl)amine hydrochloride and1-butylimidazole in 2-propanol. The tricationic compound with the anionof NTf₂ is synthesized by the metathesis reaction of the chloridecompound with LiNTf₂ in NaOH water solution.

Example 8 Synthesis of Central Nitrogen Based-Tricationic Liquid Salt

For an example, as shown in Scheme 8, the ionic compound with chlorideis obtained by refluxing tris(2-chloroethyl)amine hydrochloride and1-butylpyrrolidine in 2-propanol. The tricationic compound with theanion of NTf₂ is synthesized by the metathesis reaction of the chloridecompound with LiNTf₂ in NaOH water solution.

Following similar synthetic procedures, the phosphonium orpyrrolidinium-based ionic liquids of the invention can be obtained.

Example 9 Synthesis of Tricationic Chiral Liquid Salt

The ionic compound with bromide is obtained by refluxing1,3,5-tris(bromomethyl)benzene and(S)-(1-methylpyrrolidin-2-yl)-methanol in 1,4-dioxane. Then, the ioniccompound with the desired anion is synthesized by the metathesisreaction.

Example 10 Synthesis of Tricationic Chiral Liquid Salt

The ionic compound with bromide is obtained by refluxing1,3,5-tris(bromomethyl)benzene and(S)-2-dimethylamino-3-methyl-butan-1-ol in 1,4-dioxane. Then, the ioniccompound with the desired anion is synthesized by the metathesisreaction.

Example 11 Synthesis of Tricationic Chiral Liquid Salt

The ionic compound with bromide is obtained by refluxing1,3,5-tris(bromomethyl)benzene and(R,R)-2-dimethylamino-1-phenyl-propan-1-ol in 1,4-dioxane. Then, theionic compound with the desired anion is synthesized by the metathesisreaction.

Example 12 Synthesis of C2 Symmetric Central Phenyl-Based Liquid Salt

1,2,3-Tris-bromomethyl-benzene is synthesized as shown in Scheme 12.Then, the C2 symmetric trigeminal tricationic liquids are obtained bythe similar synthetic procedures as described in Example 1.

Example 13 Synthesis of Unsymmetric Central Phenyl-Based Liquid Salt

1,2,4-Tris-bromomethyl-benzene is synthesized as shown in Scheme 13.Then, the unsymmetrical trigeminal tricationic liquids 6a-d are obtainedby the similar synthetic procedures as described in Example 1.

Example 14 Synthesis of a Branched Tetrageminal Tetracationic LiquidSalt

As shown in Scheme 14, the tetracationic compound with bromide isobtained by refluxing butylimidazole and1,2,4,5-tetrakis(bromomethyl)benzene in 1,4-dioxane. Then, the ionicliquid compound with the desired anion is synthesized by the metathesisreaction.

Example 15 Synthesis of a Tetracationic Liquid Salt Based on Ammonium

As shown in Scheme 15, the tetracationic compound based on ammonium issynthesized by the quaternisation reaction of haloalkane and Mannichbase of 2,5-dimethylpyrrole. Then, the ionic liquid compound with thedesired anion is synthesized by the metathesis reaction.

Example 16 Synthesis of a Trianionic Liquid Salt

As shown in Scheme 16, the triol compound is sulfated by chlorosulfonicacid. Then, the sulfate-based trianionic ionic liquid is obtained by anacid-base neutralization reaction with tertiary anime.

Example 17 Synthesis of a Linear Trigeminal Tricationic Liquid Salt

As shown in Scheme 7, the tricationic compound with bromide is obtainedby reactions of sodium imidazole and (5-bromopentyl)-trimethylammoniumbromide. Then, the ionic liquid compound with the desired anion issynthesized by the metathesis reaction.

Example 18 Synthesis of a Linear Unsymmetrical Trigeminal TricationicLiquid Salt

As shown in Scheme 8, an unsymmetrical tricationic compound issynthesized by similar synthetic procedures as described above.

Example 19 Synthesis of a Linear Tetrageminal Tetracationic Liquid Salt

As shown in Scheme 19, the linear tetracationic compound with bromide isobtained by refluxing alkyldiimidazole and(5-bromopentyl)-trimethylammonium bromide in isopropanol. Then, theionic liquid compound with the desired anion is synthesized by themetathesis reaction.

Example 20

Use of Polycationic Liquid Salts as Reagents in ESI-MS for the Detectionof Anionic Molecules

Tricationic Reagent:

Table 1 gives the structure of the seventeen cationic reagents used inthis study.

TABLE 1 Trications Core Charged GroupsA1A2A5A6B1B2B4B6C1C2C3C4C5C6C7D2D6

After purification, the tricationic salts were exchanged to the fluorideform using the procedure reported previously with some modifications.The same amount (4 mL) of anion exchange resin was packed into adisposable 10 mL syringe and put into the fluoride form by washing thecolumn with ten column volumes of 1 M NaOH followed by ten columnvolumes of water, seven volumes of 0.5 M NaF, and ten volumes of water.The tricationic reagents were dissolved in either water or methanol at aconcentration of 0.05M and one milliliter of this solution was passedthrough the resin and eluted by water into a volumetric flask. Thisstock solution was diluted with water to make the working tricationicreagent solution at concentration such that when it was mixed with thecarrier solvent the concentration of the reagent was 10 μM.

ESI-MS:

ESI-MS analysis was carried out on a LXQ (Thermo Fisher Scientific SanJose, Calif., USA) linear ion trap. A Surveyor MS pump (Thermo FisherScientific) with a vacuum degasser provided the carrier flow (67%MeOH/33% Water) at 300 μL/min. The tricationic reagent was introduced tocarrier flow using a Y-type tee and a Shimadzu 6A LC pump operated at100 μL/min was used for this purpose. For analysis in negative modewater replaced the aqueous tricationic reagent solution. The test anionswere introduced into the carrier solvent using a six-port injectionvalve located between the Surveyor MS pump and the Y-type tee. ESIionization conditions for positive and negative ion modes along with theoptimized parameters for fluorophosphates are listed in Table 2.

TABLE 2 MS parameters General General Optimized MS Parameters PositiveMode Negative Mode for FPO₃ Spray Voltage (kV) 3 −5 4.7 Capillary temp(° C.) 350 250 350 Capillary Voltage (V) 11 28 −21 Tube lens (V) 105 95−96 Sheath gas (AU) 37 37 37 Auxiliary gas (AU) 6 6 6 (AU): arbitraryunits

Detection limits (defined as S/N=3) for the eleven anions weredetermined by five replicate injections. The mass spectrometer wasoperated in single ion monitoring mode for the determination of alllimits of detection (LODs). Data analysis was performed in Xcalibur 3.1software.

Results and Discussion:

Eleven divalent anions were used to evaluate seventeen differenttricationic reagents (see Table 1). The anions included both inorganicand organic types and were structurally diverse. Metal-based anions suchas dichromate, nitroprusside, and hexachloroplatinate were among theinorganic anions included. Some of the anions were chosen based on thebehavior of singly charged anions with dicationic reagents. Singlycharged anions with halogen atoms paired very well with dicationicreagents and so representative divalent anions with bromine or fluorineatoms (bromosuccinate, dibromosuccinate, fluorophosphates) also wereincluded in this study.

The trications synthesized for this study had one of four different“core” structures (Table 1). A and B have a benzene core while thenitrogen at the middle of core C is less hydrophobic. D is by far themost flexible of the four core structures. Seven different chargecarrying groups were used to create the seventeen tricationic reagents.Trications are named by the core used (A, B, or C) and the type ofcharged group (1-7). For example, trication A1 has the benzene core andbutyl imidazolium charged groups.

The detection limits for the anions in the positive mode by ESI-MS arein Table 2.

TABLE 2 Detection limits of doubly charged anions with tricationicreagents Sulfate Dichromate Oxalate Thiosulfate Trication LOD (ng)Trication LOD (ng) Trication LOD (ng) Trication LOD (ng) B1 1.00E−01 B14.58E−01 C6 1.50E−02 A6 1.25E−01 B4 1.00E−01 B4 2.00E÷00 A1 4.00E−02 C11.25E−01 A5 1.00E−01 A6 1.00E÷01 B1 4.00E−02 B2 1.50E−01 C3 1.25E−01 C41.00E÷01 B6 2.34E−01 C5 1.53E−01 D6 1.50E−01 B2 1.00E÷01 A6 2.50E−01 B41.61E−01 C4 2.50E−01 A1 1.02E÷01 C1 3.43E−01 C4 2.00E−01 B2 2.50E−01 A21.25E÷01 C3 3.75E−01 B1 2.41E−01 A1 5.00E−01 B6 1.49E÷01 C4 4.35E−01 B62.60E−01 A6 5.00E−01 C2 1.73E÷01 A2 4.99E−01 C6 4.50E−01 A2 6.25E−01 C11.75E÷01 A5 5.00E−01 C3 4.99E−01 D2 7.00E−01 C3 2.00E÷01 B2 5.00E−01 A27.50E−01 C2 7.50E−01 C5 2.50E÷01 C2 7.18E−01 C2 7.80E−01 C1 8.75E−01 C64.50E÷01 B4 7.50E−01 A1 1.00E+00 B6 1.50E+00 D6 4.88E÷01 D6 8.75E−01 D21.38E+00 C5 1.88E+00 C7 4.96E÷01 C5 1.00E+00 A5 2.14E+00 C6 2.38E+00 A51.75E÷02 D2 1.50E+00 C7 5.20E+00 C7 2.75E+00 D2 2.50E÷02 C7 4.28E+00 D61.50E+01 Nitroprusside Bromosuccinate o-benzenedisulfonateHexachloroplatinate Trication LOD (ng) Trication LOD (ng) Trication LOD(ng) Trication LOD (ng) B4 3.22E−03 A6 7.50E−02 A6 1.50E−02 B4 2.60E−02A6 7.50E−03 B6 4.99E−01 C1 2.25E−02 B1 3.90E−02 B1 8.55E−03 C3 5.00E−01B1 2.50E−02 A6 7.50E−02 B6 1.38E−02 D6 5.00E−01 B4 2.50E−02 C1 1.00E−01C4 2.00E−02 C6 7.50E−01 C4 3.00E−02 A1 1.30E−01 C1 2.73E−02 A5 1.50E÷00C6 3.75E−02 B6 1.58E−01 C5 2.73E−02 C5 1.63E÷00 A1 5.00E−02 B2 2.00E−01C3 4.25E−02 A2 4.99E÷00 C2 5.00E−02 C4 2.50E−01 A1 4.29E−02 C1 5.00E÷00B6 5.00E−02 D6 5.00E−01 C2 4.42E−02 B2 5.00E÷00 C5 5.00E−02 C5 8.75E−01A2 4.86E−02 C2 7.00E÷00 A2 7.50E−02 C3 1.00E+00 C7 6.00E−02 A1 7.50E÷00C3 1.25E−01 C2 1.05E+00 B2 1.00E−01 C4 8.75E÷00 D6 1.50E−01 A2 1.58E+00D6 1.25E−01 B4 1.00E÷01 A5 2.00E−01 C7 1.58E+00 C6 2.00E−01 D2 1.25E÷01C7 3.75E−01 C6 2.00E+00 A5 3.15E−01 B1 1.75E÷01 B2 1.13E+00 D2 2.13E+00D2 8.75E−01 C7 4.50E÷01 D2 1.75E+00 A5 2.25E+00

Except for dichromate, detection limits for most of the anions were inthe hundreds of picograms to nanogram range with the tricationicreagents. The trications are arranged from lowest to highest accordingto the determined LODs. Using this arrangement, there are a few trendsthat emerge. From Table 2 it becomes obvious that trications A6 and B1provide good sensitivity for a broad range of the representativedivalent anions. A6 (1,3,5-tris-(tripropylphosphonium) methylbenzenetrifluoride) performs the best overall since it ranks as one of the topthree tricationic reagents for all of the anions except sulfate andoxalate. Even then, it ranks as the fifth best tricationic reagent fordetecting oxalate. Trication B1 (1,3,5-tris-(1-(3-butylimidazolium))methyl-2,4,6-trimethylbenzene trifluoride) also does well, but is in thetop three less consistently than A6. Table 2 also shows that tricationC7 does not pair well with any anion, making it the most ineffectiveadditive tested. A5 also ranked in the lower half of the trication listfor many of the anions. These two tricationic reagents would be poorchoices for developing a sensitive method for the detection of divalentanions by positive ion mode ESI-MS.

When the terminal cationic moieties of the trication are the same, it ispossible to compare the effect of the core structure on the performanceof the tricationic reagent. While there are exceptions, cores A and Btend to pair more effectively with the doubly charged anions than thosebased on core C. For these eleven anions, a tricationic reagent with a Ccore performs in the top three only four times. Thus, a tricationicreagent with a more rigid aromatic core seems to produce better results.However, the decision whether or not to include methyl groups assubstituents on the benzene core is less straightforward. When thecharged group is phosphorus-based, the plain benzene core (A1) providedlower detection limits compared to the mesitylene(1,3,5-trimethylbenzene) core (B6). However, the opposite trend was seenin comparing A1 and B1. A1 seemed to be more susceptible to the loss ofone of the butyl imidazole groups under MS conditions (data not shown)than B1, which appears to be stabilized by the methyl groups on themesitylene core. It should also be noted that these cores may havelimited flexibility due to the repulsion among their identically chargedmoieties. Flexibility of the pairing agent was found to be an importantfactor in the pairing of singly charged anions with dicationic reagents.Trications D2 and D6 are more flexible due to their longer chains.However, these trications do not provide good sensitivity for anydivalent anions except fluorophosphates. This core structure has severalheteroatoms and carbonyl groups which could compromise its effectivenessas a gas phase ion pairing agent that can provide good detection limits.It seems that a more ideal tricationic core would use longer (perhapssolely) hydrocarbon chains to attach the charged groups to a hydrophobiccore. This would reduce charge repulsion and increase flexibility.

The nature of the terminal charged groups also influenced the detectionlimits observed for the anions. For example, the phosphonium basedtricationic reagents (A6, B6, and C6) generally paired well with all ofthe anions. Benzyl imidazolium groups provided the lowest detectionlimits for nitroprusside and hexachloroplatinate and decent detectionlimits for o-benzenedisulfonate. This seems to indicate that pi-pi andn-pi interactions play a role in the association of certain specificanions with tricationic reagents. Analogous trends were seen withdicationic reagents. However, two of the charged groups that did wellwith the dicationic reagents gave lower than expected sensitivities forthe representative anions in this study. Reagents with methylimidazolium and pyrrolidinium groups consistently placed in the middleto lower half of the trications tested regardless of the core structure.Instead, butyl imidazolium groups on the mesitylene core (B) performedbetter than expected.

It should be noted that the empirical data presented here are the resultof several factors in addition to the binding affinity of the anions tothe tricationic reagent. A single set of instrumental settings was usedfor the evaluation of the tricationic reagents. Some variance ininstrumental performance between the different complexes is to beexpected. The detection limit for oxalate was lowered from 250 pg to 75pg when conditions were completely optimized (see experimental) for theoxalate/A6 complex. This increase in sensitivity is similar to that seenwhen optimizing dicationic reagents for detecting singly charged anions.Increasing the spray voltage and decreasing the capillary temperaturehad the biggest impact on the signal intensity.

FIG. 3 shows a comparison of signal to noise ratios in the positive andnegative ion modes for the two anions hexachloroplatinate and0-benzenedisulfonate. In both cases, using a tricationic reagent in thepositive mode produced superior signal to noise ratios even though tentimes less sample was injected. By detecting divalent anions in thepositive mode as a complex, the sensitivity for the two anions increasesby almost two orders of magnitude. This demonstrates the ability oftricationic reagents to improve the sensitivity of mass spectrometry fordivalent anions.

CONCLUSIONS

Seventeen tricationic reagents have been evaluated as pairing agents fordetecting eleven doubly charged anions in the positive mode by ESI-MS.Structural features of the tricationic reagents including the terminalcharged groups and the core structure influenced the detection limitsfor the doubly charged anions. The use of tricationic reagents in thepositive ion mode increased the signal to noise ratios ofhexachloroplatinate and O-benzenedisulfonate compared to negative modeeven though ten times more sample was injected in the negative ion mode.

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1. A polyionic liquid salt comprising a polyionic species thatcorresponds in structure to Formula I:Gc(A)_(m)  (I) and at least one counterion; Gc is a non-chargedsubstitutable central group selected from the group consisting ofnitrogen atom, phosphorous atom, silicon atom, alkyl, carbocyclyl, andheterocyclyl; wherein the nitrogen atom optionally is substituted withone or more substituents selected from the group consisting of alkyl andalkylcarbonylaminoalkyl; wherein Gc optionally is further substitutedwith one or more R_(c) substituents independently selected from thegroup consisting of alkyl, cycloalkyl, phenyl, halo, alkoxy andhydroxyl; each A is an independently selected monoionic group, wherein:the monoionic group is selected from the group consisting of alkylene,alkenylene, alkynylene, (—CH₂-carbocyclyl-CH₂—)_(n), and polysiloxyl;wherein alkylene, alkenylene, and alkynylene optionally contain one ormore heteroatoms selected from the group consisting of O, N, S and Si;wherein the monoionic group is substituted with a cationic groupselected from the group consisting of heterocyclyl, ammonium andphosphonium; wherein the cationic group optionally is substituted withone or more substituents independently selected from the groupconsisting of alkyl, cycloalkyl, phenyl, halo, alkoxy and hydroxyl;wherein the alkyl optionally is substituted with one or moresubstituents selected from the group consisting of hydroxy and phenyl;or the monoionic group is an anionic group selected from the group ofsubstituents consisting of carboxylate, sulfonate and sulfate; whereineach such substituent is optionally substituted with one or moresubstituents independently selected from the group consisting of alkyl,carbocyclyl and heterocyclyl; n is selected from the group consisting of1 to 20, inclusive; and m is selected from the group consisting of 3, 4,5 and
 6. 2. The polyionic liquid salt of claim 1, wherein each A isindependently selected from the group consisting of:

wherein each R₁, R₂, R₃ and R_(n) are independently selected from thegroup consisting of hydrogen, alkyl, hydroxyalkyl, carbocyclyl,heterocylyl, halo, alkoxy, and hydroxyl.
 3. The polyionic liquid salt ofclaim 2, wherein the polyionic species corresponds in structure to aformula selected from the group consisting of:


4. The polyionic liquid salt of claim 3, wherein the polyionic speciesis selected from the group consisting of:


5. The polyionic liquid salt of claim 4, wherein the at least onecounterion is independently selected from the group consisting of Br⁻,BF₄ ⁻, PF₆ ⁻, NTf₂ ⁻, TfO⁻,

wherein R is selected from the group consisting of hydrogen, alkyl,hydroxyalkyl, carbocyclyl, heterocylyl, halo, alkoxy, hydroxyl,alkylcarbonyl, alkylcarbonylalkylene, hydroxycarbonyl,

wherein X₁ is C₁-C₁₀-alkylene; X₂ is selected from the group consistingof hydrogen, alkyl, alkoxy, amino and hydroxy; Y₁ is selected from thegroup consisting of hydrogen and alkyl; and Y₂ is C₁-C₁₀-alkylene. 6.The polyionic liquid salt of claim 5, wherein there are at least threecounterions.
 7. The polyionic liquid salt of claim 3, wherein thepolyionic liquid salt has the formula:


8. The polyionic liquid salt of claim 7, wherein the at least onecounterion is selected from the group consisting of Br⁻, BF₄ ⁻, PF₆ ⁻,NTf₂ ⁻, TfO⁻,

wherein R is selected from the group consisting of hydrogen, alkyl,hydroxyalkyl, carbocyclyl, heterocylyl, halo, alkoxy, hydroxyl,alkylcarbonyl, alkylcarbonylalkylene, hydroxycarbonyl,

wherein X₁ is C₁-C₁₀-alkylene; X₂ is selected from the group consistingof hydrogen, alkyl, alkoxy, amino and hydroxy; Y₁ is selected from thegroup consisting of hydrogen and alkyl; and Y₂ is C₁-C₁₀-alkylene. 9.The polyionic liquid salt of claim 8, wherein there are at least threecounterions.
 10. The polyionic liquid salt of claim 3, wherein eachmonoionic group has one or more chiral centers.
 11. The polyionic liquidsalt of claim 10, wherein the polyionic species is selected from thegroup consisting of:

wherein each of the asterisks represents a chiral center; and each R_(A)is independently selected from the group consisting of hydrogen, alkyl,cycloalkyl, phenyl, halo, alkoxy and hydroxyl.
 12. The polyionic liquidsalt of claim 11, wherein the polyionic species is selected from thegroup consisting of:


13. The polyionic liquid salt of claim 2, wherein the polyionic speciesis selected from the group consisting of:


14. The polyionic liquid salt of claim 13, wherein the polyionic speciesis selected from the group consisting of:


15. The polyionic liquid salt of claim 14, wherein the at least onecounterion is selected from the group consisting of Br⁻, BF₄ ⁻, PF₆ ⁻,NTf₂ ⁻, TfO⁻,

wherein R is selected from the group consisting of hydrogen, alkyl,hydroxyalkyl, carbocyclyl, heterocylyl, halo, alkoxy, hydroxyl,alkylcarbonyl, alkylcarbonylalkylene, hydroxycarbonyl,

wherein X₁ is C₁-C₁₀-alkylene; X₂ is selected from the group consistingof hydrogen, alkyl, alkoxy, amino and hydroxy; Y₁ is selected from thegroup consisting of hydrogen and alkyl; and Y₂ is C₁-C₁₀-alkylene. 16.The polyionic liquid salt of claim 15, wherein there are at least threecounterions.
 17. The polyionic liquid salt of claim 2, wherein thepolyionic species corresponds in structure to a formula selected fromthe group consisting of:


18. The polyionic liquid salt of claim 17, wherein the polyionic speciesis


19. The polyionic liquid salt of claim 18 wherein the at least onecounterion is selected from the group consisting of Br⁻, BF₄ ⁻, PF₆ ⁻,NTf₂ ⁻, TfO⁻,

wherein R is selected from the group consisting of hydrogen, alkyl,hydroxyalkyl, carbocyclyl, heterocylyl, halo, alkoxy, hydroxyl,alkylcarbonyl, alkylcarbonylalkylene, hydroxycarbonyl,

wherein X₁ is C₁-C₁₀-alkylene; X₂ is selected from the group consistingof hydrogen, alkyl, alkoxy, amino and hydroxy; Y₁ is selected from thegroup consisting of hydrogen and alkyl; and Y₂ is C₁-C₁₀-alkylene. 20.The polyionic liquid salt of claim 19, wherein there are at least fourcounterions.
 21. The polyionic liquid salt of claim 2, wherein thepolyionic species corresponds in structure:

wherein z is selected from the group consisting of 1 to 20, inclusive.22. The polyionic liquid salt of claim 21, wherein the polyionic speciescorresponds in structure to:

wherein each R_(A) is independently selected from the group consistingof hydrogen, alkyl, cycloalkyl, phenyl, halo, alkoxy and hydroxyl. 23.The polyionic liquid salt of claim 22, wherein the at least onecounterion is selected from the group consisting of Br⁻, BF₄ ⁻, PF₆ ⁻,NTf₂ ⁻, TfO⁻,

wherein R is selected from the group consisting of hydrogen, alkyl,hydroxyalkyl, carbocyclyl, heterocylyl, halo, alkoxy, hydroxyl,alkylcarbonyl, alkylcarbonylalkylene, hydroxycarbonyl,

wherein X₁ is C₁-C₁₀-alkylene; X₂ is selected from the group consistingof hydrogen, alkyl, alkoxy, amino and hydroxy; Y₁ is selected from thegroup consisting of hydrogen and alkyl; and Y₂ is C₁-C₁₀-alkylene. 24.The polyionic liquid salt of claim 23, wherein there are at least fourcounterions.
 25. The polyionic liquid salt of claim 2, wherein thepolyionic species corresponds in structure to:


26. The polyionic liquid salt of claim 25, wherein the polyionic speciesis selected from the group consisting of:


27. The polyionic liquid salt of claim 26, wherein the at least onecounterion is selected from the group consisting of Br⁻, BF₄ ⁻, PF₆ ⁻,NTf₂ ⁻, TfO⁻,

wherein R is selected from the group consisting of hydrogen, alkyl,hydroxyalkyl, carbocyclyl, heterocylyl, halo, alkoxy, hydroxyl,alkylcarbonyl, alkylcarbonylalkylene, hydroxycarbonyl,

wherein X₁ is C₁-C₁₀-alkylene; X₂ is selected from the group consistingof hydrogen, alkyl, alkoxy, amino and hydroxy; Y₁ is selected from thegroup consisting of hydrogen and alkyl; and Y₂ is C₁-C₁₀-alkylene. 28.The polyionic liquid salt of claim 27, wherein there are at least threecounterions.
 29. The polyionic liquid salt of claim 2, wherein thepolyionic species corresponds in structure to:


30. The polyionic liquid salt of claim 29, wherein the polyionic speciesis selected from the group consisting of:


31. The polyionic liquid salt of claim 30, wherein the at least onecounterion is selected from the group consisting of Br⁻, BF₄ ⁻, PF₆—,NTf₂ ⁻, TfO⁻,

wherein R is selected from the group consisting of hydrogen, alkyl,hydroxyalkyl, carbocyclyl, heterocylyl, halo, alkoxy, hydroxyl,alkylcarbonyl, alkylcarbonylalkylene, hydroxycarbonyl,

wherein X₁ is C₁-C₁₀-alkylene; X₂ is selected from the group consistingof hydrogen, alkyl, alkoxy, amino and hydroxy; Y₁ is selected from thegroup consisting of hydrogen and alkyl; and Y₂ is C₁-C₁₀-alkylene. 32.The polyionic liquid salt of claim 31, wherein there are at least threecounterions.
 33. The polyionic liquid salt of claim 2, wherein thepolyionic species corresponds in structure to:

wherein each t is independently selected from the group consisting of 1to 20, inclusive.
 34. The polyionic liquid salt of claim 33, wherein thepolyionic species corresponds in structure to a formula selected fromthe group consisting of:


35. The polyionic liquid salt of claim 34, wherein the at least onecounterion is selected from the group consisting of Br⁻, BF₄ ⁻, PF₆ ⁻,NTf₂ ⁻, TfO⁻,

wherein R is selected from the group consisting of hydrogen, alkyl,hydroxyalkyl, carbocyclyl, heterocylyl, halo, alkoxy, hydroxyl,alkylcarbonyl, alkylcarbonylalkylene, hydroxycarbonyl,

wherein X₁ is C₁-C₁₀-alkylene; X₂ is selected from the group consistingof hydrogen, alkyl, alkoxy, amino and hydroxy; Y₁ is selected from thegroup consisting of hydrogen and alkyl; and Y₂ is C₁-C₁₀-alkylene. 36.The polyionic liquid salt of claim 35, wherein there are at least threecounterions.
 37. The polyionic liquid salt of claim 1, wherein each A isa cationic group independently selected from the group consisting of:

wherein each R₁, R₂, R₃ and R_(n) are independently selected from thegroup consisting of hydrogen, alkyl, hydroxyalkyl, cycloalkyl, phenyl,halo, alkoxy, and hydroxyl; or each A is an anionic group independentlyselected from the group consisting of carboxylate, sulfonate andsulfate; wherein each such substituent is optionally substituted withone or more substituents independently selected from the groupconsisting of alkyl, carbocyclyl and heterocyclyl.
 38. The polyionicliquid salt of claim 37, wherein the polyionic species corresponds instructure to:


39. The polyionic liquid salt of claim 38, wherein the polyionic speciesis selected from the group consisting of:


40. The polyionic liquid salt of claim 39, wherein if A is cationic, theat least one counterion is selected from the group consisting of Br⁻,BF₄ ⁻, PF₆ ⁻, Tf₂N⁻, TfO⁻,

wherein R is selected from the group consisting of hydrogen, alkyl,hydroxyalkyl, carbocyclyl, heterocylyl, halo, alkoxy, hydroxyl,alkylcarbonyl, alkylcarbonylalkylene, hydroxycarbonyl,

wherein X₁ is C₁-C₁₀-alkylene; X₂ is selected from the group consistingof hydrogen, alkyl, alkoxy, amino and hydroxy; Y₁ is selected from thegroup consisting of hydrogen and alkyl; Y₂ is C₁-C₁₀-alkylene; and if Ais anionic, the at least one counterion is selected from the groupconsisting of quaternary ammonium, protonated tertiary amine,phosphonium and arsonium.
 41. The polyionic liquid salt of claim 40,wherein there are at least three counterions.
 42. A polyionic liquidsalt comprising a polyionic species having Formula (III), (IV) or (V):

and at least one counterion; wherein each B is independently selectedfrom the group consisting of alkylene, alkenylene, alkynylene,(—CH₂-carbocyclyl-CH₂—)_(n), and polysiloxyl; wherein alkylene,alkenylene, and alkynylene optionally contain one or more heteroatomsselected from the group consisting of O, N, S or Si; wherein B isoptionally substituted with one or more substituents selected from thegroup consisting of alkyl, alkenyl, alkynyl, and alkoxy; each A is anindependently selected monoionic group, wherein: the monoionic group isa cationic group selected from the group consisting of heterocyclyl,ammonium and phosphonium; wherein the cationic group optionally issubstituted with one or more substituents independently selected fromthe group consisting of alkyl, cycloalkyl, phenyl, halo, alkoxy andhydroxyl; wherein the alkyl optionally is substituted with one or moresubstituents selected from the group consisting of hydroxy and phenyl;or the monoionic group is an anionic group selected from the group ofsubstituents consisting of carboxylate, sulfonate and sulfate; whereineach such substituent is optionally substituted with one or moresubstituents independently selected from the group consisting of alkyl,carbocyclyl and heterocyclyl; n is selected from the group consisting of1 to 20, inclusive.
 43. The polyionic liquid salt of claim 42, whereineach A is independently selected from the group consisting of:

wherein each R₁, R₂, R₃ and R_(n) are independently selected from thegroup consisting of hydrogen, alkyl, hydroxyalkyl, cycloalkyl, phenyl,halo, alkoxy, and hydroxyl.
 44. The polyionic liquid salt of claim 43,wherein the polyionic species is selected from the group consisting of:

wherein each v is independently selected from the group consisting of1-20, inclusive.
 45. The polyionic liquid salt of claim 44, wherein theat least one counterion is selected from the group consisting of Br⁻,BF₄ ⁻, PF₆ ⁻, NTf₂ ⁻, TfO⁻,

wherein R is selected from the group consisting of hydrogen, alkyl,hydroxyalkyl, carbocyclyl, heterocylyl, halo, alkoxy, hydroxyl,alkylcarbonyl, alkylcarbonylalkylene, hydroxycarbonyl,

wherein X₁ is C₁-C₁₀-alkylene; X₂ is selected from the group consistingof hydrogen, alkyl, alkoxy, amino and hydroxy; Y₁ is selected from thegroup consisting of hydrogen and alkyl; and Y₂ is C₁-C₁₀-alkylene. 46.The polyionic liquid salt of claim 45, wherein there are at least threecounterions.
 47. A solvent comprising one or more polyionic liquid saltsof claim 1 or
 42. 48. A device for chemical separation or analysiscomprising a solid support and one or more polyionic liquid salts ofclaim 1 or 42, wherein the one or more polyionic liquid salts isadsorbed, absorbed or immobilized on the solid support.
 49. The deviceof claim 48, wherein the solid support is packed in a chromatographiccolumn.
 50. The device of claim 48, wherein the solid support is acapillary column.
 51. The device of claim 48, further comprising asyringe having a hollow needle defining an inner space, the needle beingdisposed at an end of a barrel and a plunger disposed within the barrel,the solid support being attached to the syringe such that it isretracted into the inner space of the needle when the plunger isretracted from the barrel and exposed from within the needle when theplunger is inserted into the barrel.
 52. The device of claim 48, whereinthe one or more polyionic liquid salts is immobilized on the solidsupport and wherein the one or more polyionic liquid salts contains atleast one unsaturated group which can facilitate cross-linking orimmobilization.
 53. The device of claim 51, wherein said syringe is amicrosyringe.
 54. A method for separating one chemical from a mixture ofchemicals comprising: providing a mixture of at least one first and atleast one second chemical, exposing the mixture to a solid supportcontaining one or more polyionic liquid salts of claim 1 or 42 whereinthe one or more polyionic liquid salts is adsorbed, absorbed orimmobilized on the support, and retaining at least a portion of thefirst chemical on the solid support.
 55. The method of claim 54, whereinthe solid support is a column and the mixture is passed through thecolumn such that elution of the first chemical is prevented or delayed.56. The method of claim 55, wherein the column is a capillary column.57. The method of claim 54, wherein the mixture is carried in a gaseousmobile phase.
 58. The method of claim 54, wherein the solid support isattached to a microsyringe having a hollow needle defining an innerspace, the needle being disposed at an end of a barrel and a plungerdisposed within the barrel, the solid support being attached to themicrosyringe such that it may be retracted into the inner space of theneedle when the plunger is retracted from the barrel and exposed fromwithin the needle when the plunger is inserted into the barrel, exposingthe solid support from within the needle into the mixture, andretracting the solid support from the mixture, wherein it includes atleast some amount of the first chemical.
 59. A method of detecting ananion by ESI-MS, the method comprising using one or more polycationicliquid salts of claim 1 or claim
 42. 60. The method of claim 59, whereinthe one or more polycationic liquid salt is a fluoride salt.